Understanding Root Health


Hi, my name is Byron Martin, here at Logee’s Greenhouses. And today, we’re going to be talking about root health. Of all the conditions that cause stress, in terms of culture, damage to the root system is probably one of the greatest, and probably one of the more frequent. Most of the damage is caused by diseases. And those diseases are pathogens that consume the roots and kill off the roots. So, we always say that when you’re having trouble in the top of the plant; it’s looking funny; things aren’t right; the luster goes away, or the sheen goes away; plant doesn’t seem to grow; you get some damage to the leaves. Typically, would be, even micro-nutrient problems. You always check your root system. Today, we’re going to be talking a little bit about root disease; how to manage it. And, how to identify it. These are citrus. Most of these are Meyer Lemons. The majority of these have been grown in a cold greenhouse, and there’s varying degrees of stress on them. I always say that roots don’t die from old age. They die from something; and most of those somethings, as I mentioned before, are diseases. These are pathogens; fungi that attack the root system and then kill it. And so, what we’re doing is, we’re looking at some of these plants. Now, there’s some micro-nutrient deficiencies in these that could be indicative of root disease. It also can be because they’ve been grown under very cold conditions during the wintertime. There’s also, right now, a flush of growth happening– you see the flush of growth on all these tips. New growth, right here. That means that the plants are becoming– obviously, becoming active. And, it also means that the root system’s starting to become active. So, what we do is, we take a plant like– so now, these are being grown in plastic pots. This is one thing that can increase the problem of root disease, because it holds moisture for a longer period of time. But we simply would knock the plant out of the pot, and then we examine the root ball. And, here you can see, the roots on a citrus, initially, can be very white, but they will turn this kind of tan color. And you look it over. And that root system is, actually, in fairly good shape. It’s– there may be a small amount of damage here and there. That root, on the very bottom, there. But, for the most part, that’s a healthy root system. And the thing about root diseases is, the percentage of damage that it causes. I mean, something like this– it may be a 5% damage, from a few roots going by, or being affected. But, for the most part, this plant isn’t even going to be fazed by that. It’ll just keep growing. And in that case, it’s… that’s fine. Here’s one that’s been sitting in a gallon of– a plastic gallon. And, you can see, if we look at the bottom of this; it’s lost its entire root system, here. And, you can see, when we touch, it the roots simply fall apart. And, a lot of times we’ll have questions come in about ‘why my plant is not doing well,’ and we always say check your root system for healthy roots. And this means taking it; knocking it out of the pot, and just touching them. If the root system falls apart, you have some kind of damage. Now, this is a plastic pot. Water could have sat at the bottom. Possibly, could be an issue of anaerobic bacteria, or anaerobic conditions getting going, and kill the root system off. But when I smell the soil, it doesn’t smell sour. It actually smells like citrus roots. And, you can see, here, there’s a new white root coming out. And from here down is all healthy roots. So, the only place the damage occurred was at the very bottom, where there was high moisture. And, you can see, we’re starting here, in the springtime with active growth. And this plant, although it’s showing some symptoms on the leaves, of some chlorosis– nutrient deficiencies– it’s flushing new growth. The deficiencies, probably, were caused more by the cold. And this plant is going to come out of it in great shape. And, it’s actually on its way to do that. So, we consider this a healthy plant. Even though we’ve lost the very bottom root system, and you can see the damage to that. Here’s a young plant that is just starting to grow. And, you can see the root systems are nice and white. They will eventually turn tan, but that root system is in great shape. So, the question is– how do we manage that so that it doesn’t consume the plant, or we can keep our roots healthy so there is no disease? The most important thing is watering. Don’t water the plant until it’s showing dryness– into the surface of the soil, or going into a wilt. The other thing to do is to make sure that if you have plants that are prone to it– and we often mention that, when we’re talking about a particular species, or genera of plants, or whether or not they have root rot susceptibility. And many don’t. Many plants can thrive with all of water you give them, plastic pots, cold temperatures, and whatever. Other plants are susceptible to it. The most notorious of them, probably, is the gardenia; and then citrus will follow behind that. And there’s a few others that are very susceptible. When you’re growing plants that have that susceptibility, make sure that, you know, you manage the soil moisture. From dry, not to the point where you damage the plant– but dry to wet; dry to wet. Grow in clay pots, rather than these plastic pots, because that gives you a quicker dry down. Make sure that your soil has good aggregates to it, and air. Because, air is an important thing. These, we often would call these water-molds, in the sense that they live under these anaerobic, wet conditions. So, the more porous your mix is; the more open your mix is, the better it is for the root system to stay healthy. But, the most important thing is to understand the plants that are susceptible to these root diseases, and then address the environmental conditions that affect them, and you can actually circumvent damage. So, thank you for watching today. There’s a little bit of information on how to keep your roots healthy, and thus keep your plants vigorous and growing. If you’d like more information, you can visit us at logees.com

14 thoughts on “Understanding Root Health

  1. So if I find the bottom wet and rotting should I not water until the bottom dries out or should I change the soil asap.

  2. Hi! Thank you so much for these videos! I was wondering how you feel about pruning the roots of a plant (either while moving it to a larger pot, or just as maintenance when it has been in a 10-12" pot for a year or longer)? How do you usually go about pruning roots of container plants?

  3. This is my first time enjoying your YouTube channel. Great work! I’m looking forward to more great content from you. How do I use hydrogen peroxide to cure root rot in a potted fruit tree?

  4. Excellent information.

    There are very few videos on YouTube that talk about this topic as well as you have.

    Thank you πŸ™‚

  5. I do this solution to get rid of root rot or plants that aren't thriving. I gallon of water to 2 fingers of hydrogen peroxide. Shake the jug and pour over plant till saturated. Wait for to 5 days and do once more time …I guarantee you will get rid of bugs & pests. New growth will come out. Repeat if necessary..ive tested it on my houseplants & outdoor plants

  6. I cannot find a solution to my issue.

    I have a potted lime tree it’s 2 feet tall I have had it for three years and I cannot get it to push growth.

    It gives limes and for the past year and a half, I have been picking the flowers to not allow it to fruit so it can push branches and leaves because it’s really light on leaves. Can you help?

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