The Basics of Root Care in Hydroponics

The Basics of Root Care in Hydroponics

When you grow plants hydroponically, take a special interest in their roots. It’ll be much easier than it would be with soil-grown plants since, by and large, the growing media in your garden gives a more up close and personal look at the roots. When you can see how the roots are doing, you can better determine any potential issues while or before they happen. Here are the basics of root care in hydroponics to ensure your grow is bigger, healthier, and higher-yielding.

Rooting for Your Roots

Obviously, you’re concerned about every part of your plants—watching for discoloration, signs of dehydration and overwatering, disease, insects, and so on. Well, your roots are just as apt to experience all those things, so keep them in mind as well. Luckily, hydroponics, depending on the system, provides a better view and greater access to the roots. Check on them periodically for the following issues, and be assured your plants will grow better. For starters, here are some common problems encountered by roots.

Root Rot

You might find yourself in a constant fight against root rot, especially if you’re not careful with your watering and how much water your roots are exposed to. When you overwater, it’s possible to drown your plants. So, why doesn’t it happen more often with hydroponics, where plant roots are sometimes constantly soaking in water? The problem isn’t the water so much as a lack of exposure to oxygen. Yes, even though plants provide oxygen, they require a certain amount of air to “breathe” themselves. When the roots can’t get oxygen, they start to die. This creates root rot, causing the roots to slowly die. They can turn brown and black, become slimy, and may even fall away if you brush the roots.

Meanwhile, the leaves of the plant will turn yellow and begin to dry up and fall off. Root rot can sometimes be caused by a fungus, but more often with hydroponics it’s due to overwatering. To combat this, check to make sure your water is properly aerated by an air stone or pump, and check to see if your nutrient solution is at the right levels and is circulating properly. Keep roots wet but not soggy and consider adding a hydroponic root stimulator to give them a little boost of nutrition now and again.


Are your plants growing large, tall, and lovely, but also starting to tilt? Without soil the roots may have little to grip onto. Aid your healthy plants by ensuring the growing media—coco coir, gravel, sand, clay pellets, or what have you—is sufficient to help them anchor themselves and the greater part of the plant in place. You may not be growing in the earth but that doesn’t mean you can’t employ trusty gardening mainstays like wire, cages, stakes, and other means of securing and stabilizing a plant.

Root Burn

Getting back to your nutrient solution, keep track of the water’s pH and the nutrient and mineral content. Too much of anything is never good, and the chemical composition of nutrient solution can cause all sorts of problems through overfeeding. Roots can burn because of the salts in fertilizer. Too much salt sucks all the moisture out of the roots and the rest of the plant, causing discoloration and eventually death. Go easy on them, otherwise the roots will feel the effects first and take down the rest of the plant with it.

Not Too Hot, Not Too Cold, But Just Right

Monitor the temperature of the water your plants’ roots are steeping in. A major rule of thumb is to never let potted plants sit on a cold tile, concrete, or another kind of floor. Cold and heat interfere with your plants’ ability to absorb water and prevents the water from properly absorbing the necessary nutrients. Cold and hot water can also shock the plant’s root system, again interfering with its ability to receive nutrition. Cold and overheated plants can become sick, making them more susceptible to diseases and insects. Keep your plants comfy, warm, and happy, and never serve them water that’s colder or hotter than room temperature.

A Little Off the Bottom

You’re probably very familiar with trimming leaves, twigs, and branches. But roots? In soil-grown plants, roots get a miss since they’re down below, but in hydroponics, you have greater access to the literal lifelines of a plant. As discussed, root rot can result in slimy roots that easily slough off. If you inspect the roots and discover discoloration, however, you can get ahead of whatever fungus or other plant adversary is attacking the roots by snipping off the bad part. Healthy roots are nicely white. If the roots are brown toward the ends, consider trimming off the darker parts (but keep in mind whether your nutritional supplement might be “browning” them on its own). If the roots are growing wild and getting out of hand, give them a swift trim as well. As long as you stay away from the root crown where all the lateral roots meet, your plant will be fine.

More Drastic Measures

If you’re still having trouble with your roots (and the plants attached to them), it might be time for cleaning and sterilizing. Flushing and cleaning your system should already be a regular part of your hydroponic garden maintenance schedule, but slimy brown roots might be telling you that something bigger is happening and that it needs to be addressed now. Carefully withdraw your plants from their growing media. If done carefully, your plants can survive for a day, but be sure they’re kept warm and protected. Clean and sterilize the pots, tubing, pump, and other parts of your system to ensure any potential bacteria, fungi, residual salts or chemicals, or similar unhealthy materials are removed. When done, replace the grow media and plants and introduce a new and purer nutrient solution to the system. Those are the basics of root care in hydroponics. Happy growing!

The Basics of Root Care in Hydroponics
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