How can plants be grown in hydroponics, and yet not handle too much water in soil?

How can plants be grown in hydroponics, and yet not handle too much water in soil?

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It's pretty much common knowledge that plants planted in pots or soil that doesn't have good drainage can't be watered too much, or they'll "drown". Regardless of what actually happens, experience seems to show that it's true that plants planted in soil can't handle too much water in the soil.

Yet on the other hand, in hydroponics, plants can grow and grow very well indeed with their roots entirely submerged in water. Clearly, it's not about "drowning".

So what's the deal? Why do soil-planted plants die when they're watered too heavily?

(I wasn't sure if this is a Biology.SE or Gardening.SE question, but I figured it was biology since I'm looking for a more theoretical answer about what happens to the roots, rather than practical advice.)

Hydroponic Problems

Although hydroponic lettuce production has its benefits, it is not a care free system. Even if the nutritional and environmental demands of a plant are met, problems will occur without fail. It can be noted that most, if not all, of these issues are preventable with the proper care and management. Here are some of the issues I dealt with throughout my internship:

Responses to Overcrowding (Shade Avoidance)

Right plant shading out adjacent plant. The left plant will not have enough time to catch up developmentally and isn’t worth planting, hence, a loss in profit both for the cost of the wasted seed and the loss of a finished lettuce plant.

Plants are sensitive life forms. They have evolved to elicit responses due to the slightest change in environment. Plants are always reaching for the perfect amount of sunlight. Too little sunlight equates to less energy capture and over a prolonged time, death or delayed life cycles. When the lettuce seeds are planted in a foam tray, it’s a race for the seedlings to germinate and capture light. As the plants begin growing, they send out leaves to capture the sunlight. As the plant enlarges, it becomes aware of surrounding plants due to the difference in light quality (far red to red ratios). The plants will sense other plants are shading them out (a larger far red quantity) and therefore bolt up. Over time, they will begin shading out other plants.

Had the lettuce plugs been planted earlier on before this response was so extreme (possibly two weeks earlier), both plants would develop into gorgeous, phenomenal looking bundles of lettuce. It could be noted that although the second plant isn’t used, it may still be able to be planted into another batch of lettuce with proper planning and management.

Two green oakleaf lettuce in one plug

Lettuce seeds are quite small, even when covered with different fungicides, chemicals or packaged with nutrients. Be it human error or carelessness, two seeds can be placed, unintentionally, in one foam plug. Both seeds will germinate and immediately begin competing for light, nutrients and water. Many times, one plant will survive, yet, that is not always the case. If the person planting the lettuce does not notice two plants in one plug during planting (or any time before extreme physical changes occur due to the second plant), a “twinning” effect will take place.

Twinning red oakleaf lettuce plants. From this view (looking at one plant), it’s easy to see the dramatic height difference between that and the single plants per plug.

Although it may seem ideal to grow two plants in one plug as a customer, it creates havoc as a grower. This plug will break uniformity in the crop. Although many customers may see this as a plus (two plants for the price of one!), it also may create an unappetizing look for the rest of the crop. Thirdly, these two plants will shade out other plants as the day progresses. Fourthly and finally, this plug will need twice the nutrients and water to grow, which means a slightly elevated cost.

Green Bibb lettuce showing signs of tip burn

Greenhouse growing allows more control over environmental conditions. For example, torrential rain was a huge problem during my internship this summer. With silty fields, one heavy rain could equal a loss of thousands of dollars, time and wasted labor. This isn’t a problem in a greenhouse, of course. Yet, a grower can’t have everything: tip burn occurs. The plant will get too much light and oxidize, hence the brown colored burn. Although the burned areas can be pinched off, the uniformity of the crop will be lost.

To prevent this problem, a partial shade can be used to reduce the sunlight. Or, more light tolerable varieties could be utilized.

Root burn on Green Bibb lettuce. Notice the black roots around the edge, the brown roots and the beige roots located close to the center of the plant.

A nice way to determine the last possible moment to harvest a crop completely is to look for root burn. Healthy hydroponic roots will be a white, ivory color. The roots of dying plants (or stressed plants) will be a beige, brown or black color. If there is a deficit of water, which would indicate that the plant is too large to be maintained by the current amount of nutrients and water, the roots will begin to brown before the plant’s leaves show any signs of damage. So, by pulling up a few random plants (one closer to the tube, one in the middle of the channel, one closer to the end of the channel), it can be determined when to pull the rest of the plants.

When we processed lettuce, we would snip off the main portion of roots and leave a roughly 1/2 inch of roots still on the plug. Consumers would not see the root burn and would buy the plants. Had we left the root burn on, it is possible that the consumer would not purchase the plant because it did not look “perfect,” although they do not consume the roots anyways. The 1/2 inch of roots allow the plant to take up water. Given the delicate nature of lettuce, an hour of heat can create a wilting plant.


Inadequate root development of hydroponic lettuce seeds in Oasis cubes. Is it the excessive sunlight, elevated temperatures, a varietal issue, etc? What are your views on this?

Truly, inadequate root development could be the effects of all the environment, not just one component. It could be the roots are not wet enough or too wet. If the roots aren’t wet enough it may be because of excessive sunlight and elevated temperatures (think evaporation) and it could also be that the irrigation hasn’t been perfected enough. For example, we had to monitor channels frequently on very hot and cloudy/sunny changing days because the timers with the irrigation may not have been set at ideal lengths given the rate of evaporation.If the cubes are too wet, usually you can see green algae on them. Remember, algae would be competing against the lettuce. If your seeds are not germinating and have no signs of germinating (look for dried up leaves or stems, dissect the seed to see any development), I would assume the seed itself caused inadequate root germination. If you’ve been using the same seed for a fairly long time, have not ever had a problem with it, and are keeping them in an ideal or relatively stress free environment, maybe you got a “bad” batch of seeds or your seeds were kept in a way that inhibited growth. Another good point is that if the leaves aren’t capturing sunlight, energy isn’t being produced. If energy isn’t produced, the roots won’t be able to further their growth. Finally, have the nutrient requirements been met? Plants are like humans: feed them right and they are the poster child of health, feed them poorly and development (or growth) will be halted.

We are starting our lettuces in rockwool inside the headhouse at our farm for transplant into a NFT system. We have a 40% shade cloth over our channels.
We moved our seedlings inside for germination due to the heat here in Mississippi. Upon germination we move them into the nursery in the greenhouse. They have started to bolt out of the cubes and are long stemmed before they are ready for transplant.
Is this heat, humidity or both? Any advice on how to prevent this or better handle our seedlings once this happens?

It could be a variety of factors. My suggestion would be to try a few different things to see if there is a difference between seedlings. First, it the bolting caused by the density of the other seedlings? When I worked with lettuce, we did have some that were rather bolted. They were planted regardless and by maturation, it wasn’t noticeable. I was rather worried (stressed) that the plants would be inferior (read: unable to be sold), but the plants matured and looked about the same as all the others. Second, is the bolting because of the shade cloth? If the seedlings don’t have adequate light, they will bolt. Think of competition: to these seedlings, it’s either grow tall or die. Our eyes can adjust to low lighting and a few times, I’ve thought the lighting was adequate when it turned out to be inadequate. There is a light sensing device (not sure on the cost or where to get it). If this is a reoccurring issue, you could always pick one up to rule that out. Right now I’m doing some research and working with swiss chard. Our chard bolted and looks less than stellar now (as compared to when I’ve worked with it in the soil). After a week, it’s slightly corrected and by maturation, I’m sure it won’t be an issue. My kale was also bolted, but it’s already corrected a week after planting. What I’d do is plant the seedlings as soon as possible and see if the bolting is an issue by harvest. If none of this works, check with your county/state Cooperative Extension. They might be able to direct you elsewhere. Best of luck!

Soil or water?

In traditional soil-based farming, nutrients bind with the soil particles. Roots extend to such particles for obtaining food under ideal conditions and uptake becomes possible by plants only in conducive environments. In a hydroponic garden, plants simply receive their nutrition from a nutrient-dense solution. Therefore, a hydroponic system allows plants to directly uptake nutrients with the benefits of water-based, nutrient delivery systems. The solution is thus absorbed by the plant’s root, making it very easy for the plant to utilize what it needs and grow well.

This photosynthesis equation shows that plants don’t need soil to grow. As long as these elements are present, your hydroponic garden will thrive!

How Hydroponics Works

If you've ever placed a plant clipping into a glass of water in the hopes that it will develop roots, you've practiced in a form of hydroponics. Hydroponics is a branch of agriculture where plants are grown without the use of soil. The nutrients that the plants normally derive from the soil are simply dissolved into water instead, and depending on the type of hydroponic system used, the plant's roots are suspended in, flooded with or misted with the nutrient solution so that the plant can derive the elements it needs for growth.

The term hydroponics originates from the ancient Greek "hydros," meaning water, and "ponos," meaning work. It can sometimes be mistakenly referred to as aquaculture, or aquiculture, but these terms are really more appropriately used for other branches of science that have nothing to do with gardening.

­­As the population of our planet soars and arable land available for crop production declines, hydroponics will offer us a lifeline of sorts and allow us to produce crops in greenhouses or in multilevel buildings dedicated to agriculture. Already, where the cost of land is at a premium, crops are being produced underground, on rooftops and in greenhouses using hydroponic methods.

Perhaps you'd like to start a garden so that you can grow your own vegetables, but you don't have the space in your yard, or you're overwhelmed by pests and insects. This article will arm you with the knowledge you need to successfully set up a hydroponics garden in your home and provide suggestions of plants that will grow readily without a big investment.

History of Hydroponics and Soil-less Gardening

While it's easy to imagine this kind of process being labeled as a bunch of new age science fiction, hydroponics has actually been in use for thousands of years. The famous Hanging Gardens of Babylon, one of the seven wonders of the ancient world, are largely believed to have functioned according to hydroponic principles. Built around 600 B.C. in Babylonia, or Mesopotamia, the gardens were situated along the Euphrates River. The area suffered from a dry, arid climate that rarely saw rain, and it's believed that the lush gardens were watered using a chain pull system, which carried water up from the river and allowed it to trickle down to each step or landing of the garden structure.

During the 10th and 11th centuries, the Aztecs developed a system of floating gardens based on hydroponics. Driven out of their land, they settled at Lake Tenochtitlan. Unable to grow crops on the lake's marshy shore, they built rafts out of reeds and roots. These rafts were topped with a bit of soil from the bottom of the lake, and then floated out to the center of the water. Crops would grow on top of the rafts, their roots reaching through the rafts and down into the water. Marco Polo's writings indicate he witnessed similar floating gardens while visiting China in the late 13th century [source:].

Formal research and publications on hydroponics didn't begin until the 17th century. Sir Francis Bacon, a British scientist, philosopher and politician did research on soil-less gardening in the 1620s. His work on the subject was published posthumously in 1627 and sparked an incredible wave of research into hydroponics.

In 1699, another English scientist, John Woodward, performed tests involving spearmint growth in various water solutions. He attempted to grow spearmint plants in rain water, river water and water that had been mixed with soil and then drained. He found that the mint grew faster and produced healthier plants in the water solution that had been mixed with soil. His conclusion was that plants would grow better in less pure water than they would in distilled water. We know today that his results were due to minerals that remained in the water after it had been mixed with the soil [source: Glass].

­­A Berkeley scientist, William Gericke, promoted the use of hydroponics in commercial agriculture. Using a process he called "aquaculture," he touted the benefits of soil-less gardening by growing massive tomatoes in his home via water and nutrient solutions. After finding that the term "aquaculture" was already being used to describe the study of aquatic organisms, he coined the term "hydroponics," which we still use today [source: Jensen].

Two other Berkeley scientists, Dennis Hoagland and Daniel Arnon, later expanded upon Gericke's research. In 1938, they published "The Water Culture Method for Growing Plants without Soil," which is widely considered to be one of the most important texts ever published about hydroponics. Several of the nutrient solutions they developed are still used today.

According to a 1938 Time magazine article, one of the first commercial uses of hydroponics occurred during this period based on the research taking place at Berkeley. Tanks of mineralized water were used to grow beans, tomatoes, and vegetables on tiny Wake Island, a small piece of land in the Pacific Ocean. This island was used as a refueling stop for Pan-Am Airways, and the food grown there was used successfully to feed the airline's staff and crew. Similar situations occurred during World War II, as hydroponics was used to grow crops for troops on barren Pacific Islands [source: Time Magazine].

William Gericke is credited with giving hydroponics its name, but his work is often clouded by scandal. Though his hydroponic research was done while he was employed at UC Berkeley, he claimed that his work on the theory was done off the clock, in his own time. He therefore refused to share any of his work or research, and left the university before publishing his famous work on the subject, “Complete Guide to Soil-Less Gardening.” Hoagland and Arnon were given the job of trying to replicate his research, and fortunately for the future of hydroponics, they’re credited with many of their own contributions to the science [source: Time Magazine].

Why Use a Hydroponic System?

So why go through all the trouble of setting up a hydroponic system? After all, people have been growing food just fine for thousands, if not millions of years using good old-fashioned dirt. Hydroponics offers some significant benefits over traditional farming, and as word about these benefits spreads, more people will turn to hydroponics for their agricultural needs.

­First, hydroponics offers people the ability to grow food in places where traditional agriculture simply isn't possible. In areas with arid climates, like Arizona and Israel, hydroponics has been in use for decades. This science allows the people of these areas to enjoy locally grown produce and to expand their food production. Similarly, hydroponics is useful in dense urban areas, where land is at a premium. In Tokyo, hydroponics is used in lieu of traditional soil-based plant growth. Hydroponics is also useful in remotes locales, such as Bermuda. With so little space available for planting, Bermudians have turned to hydroponic systems, which take around 20 percent of the land usually required for crop growth. This allows the citizens of the island to enjoy year-round local produce without the expense and delay of importation. Finally, areas that don't receive consistent sunlight or warm weather can benefit from hydroponics. Places like Alaska and Russia, where growing seasons are shorter, use hydroponic greenhouses, where light and temperature can be controlled to produce higher crop yields.

We also must consider the significant environmental benefits to hydroponics use. Hydroponics systems require only around 10 percent of the water that soil-based agriculture requires. This is due to the fact that hydroponic systems allow recycling and reuse of water and nutrient solutions, and the fact that no water is wasted. This can have quite an impact on areas where water is scarce, such as in the Middle East and parts of Africa. Similarly, hydroponics requires little or no pesticides and only around 25 percent of the nutrients and fertilizers required of soil-based plants. This represents not only a cost savings but also benefits the environment in that no chemicals are being released into the air. Finally, we must consider the environmental impacts of transportation. As hydroponics allows produce to be grown locally and requires fewer areas to import their crops, there is a reduction in both price and greenhouse gas emissions due to reduced transportation requirements [source: Jensen].

Next, hydroponics offers us the benefit of a shorter harvest time. Plants grown in this manner have direct access to water and nutrients and therefore, are not forced to develop extensive root systems to allow them to find the nutrients they need. This saves time and produces healthier, lusher plants in about half the time as traditional agriculture.

So why isn't hydroponics taking over? This is due to several distinct disadvantages associated with these systems. The first is the high capital investment when compared with soil farming. Though hydroponics is typically much cheaper over time, it does require a substantial upfront cost to establish any sort of larger system. Next, there's the threat of power failure, which can cause pumps to stop working and ruin crops. Finally, many people fear that hydroponics requires substantial know-how and research, when in fact, it's very similar to traditional gardening. After all, plants rely on certain nutrients in order to grow, and these nutrients don't change, no matter which system you're using.

The Science Behind Hydroponic Nutrients

Before we can take a look at how hydroponics works, we must first understand how plants themselves work. Generally speaking, plants need very little to grow. They can subsist on a simple blend of water, sunlight, carbon dioxide and mineral nutrients from the soil. Plants are able to transform light energy into chemical energy to form sugars that allow them to grow and sustain themselves. Thus, plants convert carbon dioxide, water and light into sugars and oxygen through a process called photosynthesis. The photosynthesis process requires that the plant has access to certain minerals, especially nitrogen, phosphorus and potassium. These nutrients can be naturally occurring in soil and are found in most commercial fertilizers. Notice that the soil itself is not required for plant growth: the plant simply needs the minerals from the soil. This is the basic premise behind hydroponics -- all the elements required for plant growth are the same as with traditional soil-based gardening. Hydroponics simply takes away the soil requirements.

­There are several different types of hydroponic systems, though each is based on the same initial concepts. Here, we'll examine each type, discover how and why it's used and see which kinds of plants respond best to each method.

Ebb and Flow Systems require a medium, such as perlite, which serves no purpose other than to provide stability for the plant's roots. The plant derives no nutrients from the medium itself. Ebb and flow systems include a tray in which the plant is placed in a medium below the tray in a separate container is a reservoir containing water and mineral solutions. The water from the reservoir is periodically pumped up into the tray. This floods the tray and allows the plants to absorb water and nutrients. Gradually, the water drains back into the reservoir due to gravity. Ebb and Flow systems work best with small plants like herbs and are typically used in smaller hydroponic setups, such as those in the home.

Nutrient Film Technique (NFT) is a water-based system that requires no soil or mediums. They're built using wooden channels, which support polyethylene film liners. Plants such as tomatoes and cucumbers are placed on the channels, and the nutrient enriched water is pumped to the high end of each channel. The channels slope down, and water is collected at the end to be pumped back through the system and reused. Only plants with large established root systems will work with this technique.

Drip Systems are set up almost identically to an ebb and flow system, although instead of water being pumped through one large tube, it's pumped through many small tubes and drains onto the top of the plants. This system is ideal for plants that don't yet have a developed root system, and like an ebb and flow system, works best with smaller plants.

Aeroponics is another water based system, which, like NFT, requires no medium. Plants are suspended on a tray, with their roots freely dangling below. The entire tray is placed into a box that has a small amount of water and nutrient solution in the bottom. A pump system is used to draw the water up, where it's sprayed in a fine mist onto the entire plant and root in a continuous manner. This system is the most difficult to set up and manage, but it has great potential for large commercial uses.

Wick Systems are similar to ebb and flow systems in that they're medium-based. Plants are placed into a tray filled with a medium such as perlite or rockwool. At the base of each root, a nylon rope is placed, which is allowed to dangle freely, extending beyond the bottom of the tray. The entire tray is then placed on top of a reservoir. The nylon ropes absorb the water and nutrients, wicking them up to the plant's roots. This system is desirable because it requires no pumps or other equipment to be purchased [source: Roberto].

For more on what goes into setting up the different types of hydroponic systems, read on to the next section.

How NASA is learning to grow plants in space and on other worlds

When NASA sends humans to Mars, the astronauts are going to need lots of food for the trip. But freeze-dried prepackaged meals for a 2.5-year mission to the Red Planet can take up a lot of weight and room on an interplanetary vehicle. When we go to Mars, weight will be precious. The less we carry with us, the better. Plus, not all of that food is going to be super tasty — or fresh.

That’s why NASA is interested in figuring out ways to supplement astronauts’ diets with plants that can be grown in space or on other worlds. Seeds are much less weighty and spacious than already-prepared food. So scientists at NASA’s Kennedy Space Center have been experimenting with how to grow plants and vegetables in simulated space environments. Those include the microgravity environment of the International Space Station and worlds with less gravity than Earth, like the Moon and Mars.

At Kennedy, scientists experiment with different lighting and temperatures to see which environment is best for growing plants. They also simulate the conditions on the ISS to see which plants could thrive in low Earth orbit. Ultimately, NASA is trying to figure out how to grow plants with as little soil as possible, through methods like hydroponics and aeroponics. Hydroponics involves delivering water and nutrients to plant roots using liquid solutions, and with aeroponics, plants are grown in a misty air environment. Both of these methods negate the need for too much dirt, which is also heavy and takes up precious room on a rocket.

Water does behave differently in low-gravity environments. It clumps together in weird ways that it wouldn’t on Earth, making it tricky to water root plants. However, NASA has had success with growing vegetables on the International Space Station with the space agency’s Veggie experiment. Through that research, astronauts have been able to grow — and eat — plants on the ISS. The first experiment entailed growing red romaine lettuce in pillows of clay instead of soil.

Scientists are interested in potentially using interplanetary soil someday to grow plants. However, the “soil” found on the Moon and Mars isn’t really soil it’s regolith, or loose, rocky material made from volcanic ash that doesn’t have an abundance of organic materials. And the regolith on Mars isn’t exactly clean. Rovers on Mars have detected a type of salt known as perchlorates in the dirt, which can be toxic for humans if consumed in high enough quantities. It’s possible that astronauts could clean the regolith with chemical solutions or certain kinds of bacteria, but that method hasn’t been fully fleshed-out yet.

Mastering plant growth in space and on other worlds will be important to future crews traveling on long-duration missions off our planet. Not only is plant-based food important for nutrition, but supplementing a prepackaged diet with vegetables and greens could be important for stressed-out astronauts who are missing home. “We’ve heard from a lot of astronauts who comment to the effect of, ‘I thought that I’d miss the cheeseburger or pizza the most when I came back, but what I really wanted was a fresh salad,’” Gioia Massa, a NASA scientist studying food production in space at the Kennedy Space Center, tells The Verge. “So, we think having that fresh, juicy, crunchy texture in their diet can be really important.”

For the season finale of Space Craft, we visited Kennedy to taste some of the plants they’ve been experimenting with. Check out our meals in the video above.

PH Levels in Plants

Simply put, the right pH level will create an environment where your plants can absorb nutrients quickly and easily . This means your plants will be able to take in all the nutrition they need, leading to a better harvest.

Nutrient-rich water is filled with elements that are helpful to your plants. That said, if those elements aren’t broken down properly, they could cause potential harm to your grow.

The right pH level will determine the quality of helpful bacteria in your water. This bacteria helps break down elements, increasing the metabolic rate of your plants.

Here’s what to watch out for when factoring the pH level of your plants:

  • Low pH Levels — A pH level of around below 5.0 can be considered low. At this level, heavy metals like iron and aluminum change and can become toxic to your plants.
    • Symptoms of Low pH Levels in Plants — Plants affected by low pH levels typically suffer from yellowing leaves. They also experience stunted growth, wilting, and decreased update of nutrients.
    • Symptoms of High pH Levels in Plants — High pH levels often cause plants to suffer from chlorosis, which is an iron deficiency that results in yellow-white foliage. In addition, plant growth suffers due to the plant's inability to take in nutrients.

    The acidity in the water you use in your grow room determines the properties of your plants and grow medium . You'll want your plants' nutrients to be a little acidic — otherwise they can't break down. Too much acidity , though, and your nutrients can become toxic.

    So always keep in mind :

    • A pH that’s too low will be toxic to your plants.
    • A pH that’s too high means stunted growth.
    • The ideal acidity you want in your water is between 6.0 to 6.5 .

    What's the Best pH Level for My Plants?

    If you’re still unsure as to what will or won’t harm your plants as far as pH is concerned, we’ve broken down the general pH levels and their effects on plants. That way there’s no room for error, and you can ensure your plants are healthy throughout their growth cycles.

    • Below 4.0 : Root Damage
    • 4.0 to 4.9 : Nutrient Leaching
    • 5.0 to 5.9 : Good pH Level
    • 6.0 to 6.5 : Ideal pH Level
    • 6.6 to 7.0 : Acceptable pH Balance
    • 7.1 to 8.5 : Poor Nutrient Uptake
    • Above 8.5 : Root Damage

    It’s also worth mentioning that different plants thrive in varying pH levels. Some plants might thrive in levels that would be harmful to others. This is due to their acidity needs. Let’s take a look at some examples.

    • Tomatoes : 5.5 to 7.0
    • Cucumbers : 5.5 to 7.0
    • Blueberries : 4.5 to 6.0
    • Lettuce and Cabbage : 6.0 to 7.0
    • Sweet Peppers : 5.5 to 7.0
    • Hot Peppers : 6.0 to 6.8
    • Honey Locust Trees : 6.0 to 8.0

    As you can see, finding the right pH balance also depends on what you’re growing. As such, it’s worth it to do a bit of research so you know exactly how to keep your plants healthy, especially if you’re growing different types of plants that require their own unique pH balances.

    In addition, it’s important that you keep in mind that soil-grown plants tend to need a slightly higher pH than hydroponics . This is because soil retains and releases certain elements to your plants at different times . As such, take note of the following:

    • Optimal pH levels in soil range between 5.5 to 6.5 .
    • Optimal pH levels inhydroponic systems range between 6.0 to 7.0 .

    Once you know exactly what the sweet spot is for your plants, be sure to measure the soil periodically using a pH meter or monitor to ensure its pH is balanced.

      (Price: $19.99) : Using a pH meter is the most cost-efficient way to check your grow room’s pH levels. (Price: $317.10) : A pH controller is a much more sophisticated way to both monitor your plants’ pH levels and ensure they’re consistently regulated. With a controller like this, you can set the ideal pH range and let the device do the rest of the work for you. If the controller registers a change in the pH, it will automatically adjust it by either raising or lowering the acidity in your grow medium.

    How to Adjust pH Levels

    If your plants’ pH balance is too low or too high, it doesn’t necessarily mean your harvests are doomed. As far as solutions go, there are both premade and homemade options available for you to consider.

    The Best Way to Adjust Your pH

    By far the simplest solution if your plants are suffering from a pH imbalance is a premade pH buffer. As its name suggests, a premade pH buffer is a solution that has already been prepared for you. All you have to do is buy it and you’re good to go.

      (Price: $19.95) : This set of pH solutions includes both pH Up and pH Down. So whether your plants are suffering from a pH deficiency or too much acidity in their grow medium, you’ll be able to adjust their levels accordingly.
      • This type of solution is designed to raise and lower the pH of your water while keeping pH levels balanced.

      How Do You Make pH Buffers?

      You’d be surprised what you can do with everyday household items. If you’re trying to remedy a pH imbalance quickly, or if you need something while you wait to restock on a premade pH adjuster, you might have a quick solution around your house.

      • Citric Acid and White Vinegar Help Lower pH Levels : If pH levels are too high, either citric acid or white vinegar should do the trick and lower your soil’s pH.
      • Baking Soda Helps Raise pH Levels : When your plants’ pH levels are low, you can use a bit of baking soda in your solution to bring those readings up.

      In addition to being readily available, solutions like these are cost-effective and mostly easy to use. We say “mostly” because, unfortunately, it’s possible to misuse an ingredient like baking soda and see a severe spike in pH if not handled properly. As such, we recommend these as temporary solutions only . For the most part, it’s best to stick with a premade pH solution.

      General Hydroponics Aren’t Good Enough For Your Marijuana Plants

      Marijuana growers spend a lot of money on hydroponics nutrients because we want big, phat, sugary buds.

      We see marijuana growers using major hydroponics nutrients brands like General Hydroponics, Canna, House and Garden, Botanicare, and their marijuana plants grow, mature, and produce buds.

      But the question you can ask yourself is: how do hydroponics nutrients designed and tested specifically for marijuana give me the most grams and THC per watt?

      When I started growing marijuana, I used General Hydroponics 3-part base nutrients, like most people did.

      Their nutrients were easy to mix.

      I could count on getting about a pound per 1000-watt light.

      But General Hydroponics nutrients often gave me problems with pH buffering, and bloom phase performance.

      I often had to deviate from the General Hydroponics recommended mix ratios, especially when it came to the micronutrients portion of their 3-part base.

      When I called and told them their nutrients were giving me problems with my marijuana plants, they hung up as soon as I mentioned the word “marijuana.”

      It came to me right then what the company’s name tells you is that General Hydroponics nutrients are in fact general hydroponics nutrients…designed to work on lettuce, beans, and houseplants, not marijuana.

      Another time I contacted General Hydroponics, advised them I’m a legal marijuana grower, and asked for specific advice on using their hydroponics nutrients to grow marijuana.

      At least they didn’t hang up on me this time.

      But they told me General Hydroponics does not use marijuana plants in any of its testing.

      They said General Hydroponics has “nothing to do with marijuana or marijuana growers.”

      “Our products are for ornamental plants and veggies, not for illegal crops,” the General Hydroponics man said.

      Look at the General Hydroponics website or talk to their reps at an indoor gardening expo…they’ll make it clear they’re not dedicated to helping you grow bigger and better marijuana.

      That’s just not who they are.

      Their website proclaims: “We are developing new hydroponic systems and perfecting nutrient formulas to enhance flavor and yield plus vitamin and mineral content in food crops for higher nutritional value. Our farm division is testing many varieties of vegetables…”

      The obvious reaction you have to this is–hey, General Hydroponics, marijuana is not a vegetable or a food crop.

      Hydroponics insiders, including former employees of General Hydroponics, know that GH’s hydroponics ingredients, ratios, and manufacturing processes produce generic hydroponics fertilizers that have no specificity to marijuana, and GH is proud to tell you so.

      In fact, General Hydroponics avoids any event openly meant for marijuana growers.

      Take a look at this rather rude video, and you’ll see what I mean…

      When you look at a product such as General Hydroponics Flora three-part base nutrients, you see where the problems are for you and your cannabis plants.

      The problems are there because GH nutrients aren’t designed for marijuana plants.

      That’s not good, because marijuana plants have unique nutritional needs and only when you give them nutrients tailored to meet those needs do your cannabis plants give you the maximum weight and cannabinoids they’re capable of producing.

      Yes, some growers get acceptable results with General Hydroponics, or else the company would be totally out of business.

      Marijuana plants are incredibly forgiving. They can handle even the crappiest fertilizers and still give you at least a few buds.

      But the percentage of GH users who’ve had worries about their base nutrients is higher than anyone would like to see.

      When growers ask General Hydroponics, Botanicare, Technaflora or most of the other North American hydroponics nutrients companies if they do any scientific research for cannabis growing, their answer is NO and HELL NO!

      How does that make you feel?

      It made me feel I better get off the General Hydroponics and use hydroponics nutrients tested on marijuana, even if it meant switching away from what I’m familiar with.

      It’s not like General Hydroponics products are totally useless. For example, I highly recommend their mite-killer Azamax.

      They have a seaweed product called BioWeed that’s pretty nice too.

      Marijuana growers who care about their health don’t want PACLO, and public health officials have banned it in fertilizers, but GH is still making money selling it.

      The other thing is, I want to do business only with companies that embrace the marijuana growing community.

      But General Hydroponics does NOT make hydroponics nutrients for marijuana.

      It’s General Hydroponics corporate policy to deny that marijuana growers are essential to the hydroponics industry.

      All GH does is take our money selling us generic fertilizers made for veggies and ornamental plants.

      In fact, after General Hydroponics was purchased by a wholly-owned subsidiary of Scotts Miracle-Gro in early 2015, the company’s founder Lawrence Brooke bragged that GH had NEVER been designed for cannabis.

      The dude said he always made sure to distance himself and his company from marijuana growers. Wow!

      That’s why I said goodbye to GH a long time ago.

      When you want the best for your marijuana plants, you’ll stop using General Hydroponics too!

      You might also like:

      Hydroponics marijuana growers worry a lot about pH, because the pH of your root zone and hydroponics nutrients water make a big difference in your marijuana’s health and productivity. Unless&hellip

      I started growing weed two years ago but I'm not an expert marijuana grower yet. I still encounter grow room problems I can’t figure out. I used General Hydroponics 3-part&hellip

      Happy 420! If you're a marijuana grower who wants bigger yields and stickier buds, this article is our 420 gift to you. The magazine went live in May, 2011, and&hellip

      Harvesting basil—how to cue apical growth

      Basil grows at Fable: From Farm to Table

      Basil has been bred to be a single-stemmed plant growing upward. For most growers, a bushier plant is better. A pruned plant looks better, yields more, and can be easier to transport depending on your growing method.

      Upward growth is called apical growth. To change the way that basil grows, growers can trigger a secondary type of growth that moves outward and up instead of straight up. This is called lateral growth.

      A young basil plant (say 5–10 inches tall), has buds on the side of the stem that haven’t grown out yet. Those are the lateral buds they’re the back-ups that will only grow if the main stalk gets badly damaged or removed.

      This means that if growers clip the stem right above those lateral buds (a half inch or so), the buds will be triggered to grow out. By pruning basil this way, growers can increase the production of that branch and control the shape of the plant.

      When you go to harvest your basil for the first time, you’ll probably notice multiple pairs of lateral buds on the plant. Cut the plant above the second pair of buds. Matt explains why:

      “We cut down to the second ‘Y’ in most cases. Any leaves above that split on the stem will be harvested. I used to cut down to the first ‘Y’ but it made the growth so tight that I had issues with moisture being held inside within the collection of leaves. So, moving out the second has fanned out the growth enough that it doesn’t stop airflow, light penetration, etc…”

      If you prune a basil plant correctly, then you’ll see an increase in yield each time you harvest for the first three harvests (around weeks 5, 8, and 11).

      1. Check to see if your plants need water. If the soil is all dark and moist, your plant likely doesn't need water. Add water only when the soil is dry to the touch and light in color. Different plants require different amounts of water, so be sure to test each plant individually.
      2. When you have determined that the plant needs water, do so by moistening the entire root zone. Water should be exiting the drain zone when you have given enough. Water should not be applied from overhead, but rather by delivering water slowly to the base of the plant.
      3. Do not water at night. Plants that stay moist all night tend to breed disease. Only water at night if your plant has already started to wilt.
      4. Don't allow your pot to sit in standing water as it will keep the soil too wet.
      1. Move your plant to a shady area even if it is a full-sun plant. Remove any dead or dying leaves. These should be easily recognizable.
      2. Check your pot for proper drainage and, if possible, create additional air space around the roots. This will allow oxygen to reach the root zone. Remove any dead or dying roots and keep only the roots that are healthy.
      3. Water only when the soil is dry to the touch, but do not let it get too dry. You should also seize all fertilization at this point until the plant is healthy again.
      4. Treat with a fungicide.

      There is never a guarantee that your plant can bounce back from overwatering. If your plant is going to survive, you will see results within a week or so. At this point, you can move your plant back to its original location and resume watering it as normal.

      It's important to water your plants properly from the start and to make sure they have plenty of drainage. If you tend to overwater plants despite your best efforts, it might be best to avoid any plants that are more prone to problems from too much water.

      Tips for Maintaining Pothos in Water

      • Periodically, you should change the water and rinse out the vase/jar/glass that you have your Pothos growing in. This will prevent the water from becoming stagnant and foul.
      • If there is any algae buildup, clean the sides of the container.
      • If your tap water is treated with chlorine, be sure to have some prepared in advance to refill your containers.
      • As your Pothos plants grow, they may begin to grow rather long. Simply cut the tips off and root them in water. Soon, your Pothos will be growing dense and lush in whatever container you use.

      Pothos (Devil&aposs Ivy) growing in water in a glass vase

      The Hydroponic Connection

      There are people in the world who lie awake at night thinking about the perfect microgreen. We are not saying Chris Hennessy, Class of 2018, is one of those people. What we can say is that he’s more likely to be doing that sort of thing now than he was before his internship with BrightFarms.

      “My vegetable intake was never very high,” says Hennessy. “Growing up it was a struggle for me to be a healthy eater.”

      BrightFarms hydroponically farms lettuce, spinach, and other greens. It is a system of growing that allows BrightFarms to source locally-grown produce to its communities and nationwide 12 months of the year. On a most basic level, it requires trained growers, sunlight, oxygen, and water.

      It is a place Chris Hennessy almost didn’t wind up – neither hydroponics, nor BrightFarms. When it became time to find an internship in his senior year, he first pursued opportunities in the cannabis industry. When they fell through, he was fortunate to connect with a Plant Science Program alumnus working with BrightFarms.

      Chris Hennessy at BrightFarms Selinsgrove. BrightFarms: photo

      “They told me they wanted another Cobleskill student in their apprentice program. That was my intro to professional hydroponic farming.”

      It was also Hennessy’s introduction to a network of pathways SUNY Cobleskill is forging in the field of controlled environment agriculture.

      All Good Things

      The rise of hydroponic farming is not so much new as it is new on the radar. The way people think about food systems has a lot to do with that. So does the demand for clean, traceable produce. Hydroponic farming checks those boxes with companies that grow local, sell local, and identify as local.

      Growers also control the amount of water they use for their crops. The exact amount depends on the growing system. For leafy greens, farms typically use a raft system – deep water culture raft boards that, literally, raft in a controlled pool of water. Media-based growing is more common for crops like tomatoes, strawberries, and cucumbers it relies on the use of a substrate.

      A common set-up for hydroponic tomato growth. A media-based system using a substrate is common practice.

      No matter the system, hydroponic farming treats water as a carefully managed resource.

      Other variables include biological controls, like the introduction of beneficial bugs to combat any harmful bugs. There is also the fact that the amount of fuel used for transporting food is minimal, when you compare it to what is needed to source produce from regions where weather permits year-round outdoor growing.

      By setting up in the heart of local communities, hydroponic operations can also dramatically decrease the amount of time plants spend in a refrigerator before they end up on a shelf or table.

      Getting There

      Developments in all areas of hydroponic farming on the other side of the Atlantic Ocean help explain the boom in North America. European greenhouse complexes have invigorated the field. As their designs continue to inspire similar construction, greenhouse architecture and technology alone have emerged as inroads to the field of hydroponics for many in the workforce.

      That fact is not lost on students in Cobleskill.

      “We take a diverse course load,” says Jenn Hammer, Class of 2020. She interned at BrightFarms’ Selinsgrove, PA farm under new head grower Chris Hennessy (yes, the same Chris Hennessy).

      “I took weed science and soil science courses, but I also took business courses, courses in economics, nutrition… courses that were really important peripheral knowledge.”

      “You need to be qualified in your education and your experience,” adds Hennessy. “Your way into this field can be through an interest in greenhouse management, energy, sales, or architecture… It can be an interest in valves and piping, or the most technical part of the operation.”

      A tomato nursery in the Netherlands. The country is a leading designer of controlled environment growing facilities and greenhouses, inspiring new architecture around the world.

      There is also a need for industry specialists. A major employment avenue, particularly for larger-scale hydroponic operations, is integrated pest management (IPM).

      After apprenticing at BrightFarms’ Wilmington, OH farm, the company named Hennessy its head grower in Selinsgrove. His responsibilities range from controlling climate and water systems, to handling inventory management for seeds and media.

      He also oversees interns taking the exact same courses he himself completed not three years earlier. That type of connection is common in the College’s Plant Science Department.

      Hennessy interned with fellow SUNY Cobleskill Plant Science student Dave Del Pilar, and Del Pilar is now the head grower at BrightFarms Illinois. As interns, he and Hennessy worked under a supervisor who was a SUNY Cobleskill alumnus. Alumna Aimee Swett is currently an apprentice grower at BrightFarms Virginia.

      It’s Delicious – That’s It

      Jenn Hammer wanted to be a game warden before transferring to SUNY Cobleskill. Her interest in hydroponics stems from a lecture in a general biology class.

      “I come from a farming community, and as we are learning about [hydroponics] I am realizing how innovative and future-looking it is. I am thinking about how much potential there is in this industry.”

      That is yet another appeal of hydroponics – it is a field that is growing quickly, on a collision course with the future of agriculture. It is an appealing industry for new members of the workforce.

      Jenn Hammer, who interned under Head Grower Chris Hennessy at BrightFarms Selinsgrove. Hammer: photo

      “Hydroponics attracts a lot of different, innovative minds,” says Hammer. “All these new greenhouses are being built and companies are coming forward to build them. The job demand is going to be there.”

      For such a simple formula, Hammer and Hennessy find themselves doing a lot of explaining about their industry.

      “I see people every day, and I’ll spend 15 or 20 minutes just explaining what I do,” says Hammer. “They hear the passion, and the interest starts to build. I like to lay it out slowly. I talk about the local jobs angle, the fact that the product tastes incredible, the conservation of resources, the fact that everything is locally grown… You can see it start to click.”

      “People are always curious about what I do,” says Hennessy. “I have to ask if they’re ready for it when they start asking questions.”

      Peppers may be the next crop to experience a hydroponic surge, says Chris Hennessy. Large-scale hydroponic farming often moves from plant to plant. It takes time to perfect the growing techniques necessary for individual plants, even though many of the growing skills are transferable.

      Change has already come, and is coming still. The Selinsgrove farm is not even a year old, and it is BrightFarms’ largest complex. Hennessy says competitors are actively building facilities to grow tomatoes, strawberries, cucumbers, herbs, peppers, and more.

      Different levels of expertise are needed to grow the perfect tomato and the perfect pepper. But chances are it will be the best tomato and pepper you’ll taste.

      “I eat a salad for lunch because it’s delicious – that’s it,” says Hennessy. He and Hammer happen to be greens people right now, though he says many of the skills needed to hydroponically farm greens are the types of skills he could pick up if he ever wanted to move to strawberries or herbs.

      “That is where the Cobleskill education really helps. I have the knowledge to grow anything. I still have my notes, I still have my books, and I had a spot in the BrightFarms apprentice program before I graduated.”

      “We will get a call or a message and it will be (Dr. George) Crosby (from the College) and he’ll ask, ‘Hey, do you have a spot for an intern?’ We are always looking for our fellow alumni.”

      Watch the video: 8 INDOOR PLANTS THAT CAN GROW IN WATER! NO SOIL NEEDED! (July 2022).


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