In this video, Dr. Meyer covers a common issue known as Damping Off. Here is a complete transcription of the video:
What you see here are a few seedlings that have started from my summer garden. I have done some videos on how to germinate seeds and how to tell if your seedlings are doing well. I came across a little problem here that I want to share with you guys though.
What I want you to see here, notice the stem on this little squash plant. It's very thin right here and it's not growing well. The plant can't even stand up on its own. This is caused by a fungal infection, which is called damping off. Now, the other thing I want you to notice, if you can, is this other squash plant back here. There is a little gray spot right here on it. That's another sign or symptom of damping off. You're going to get gray or black or brown spots on your leaves. A lot of times you'll be able to tell that this is where a water droplet landed because when that water drop lands on the leaf, it's going to carry the fungal spores there and it's going to encourage fungal growth. Now you can also get yellowing leaves with damping off, and that's a sign of nitrogen deficiency and these spots could also mean an insect infestation.
So how do you tell if you have damping off or if it's an insect infestation or nitrogen deficiency?
Well, I have here a little plant, and you can see these roots here are white. They're vigorously growing. There's lots of them. That's what you want to look at, the roots. If your roots are small, they're stunted, (or) they have little spots on on themselves, that means you have damping off. Now, if you have damping off, (and) if this has occurred a lot, you might have to take some extreme measures to get rid of this. Mold can be very stubborn.
You're going to want to clean out your entire grow area with a 10% bleach or 20% hydrogen peroxide solution. You'll want to sterilize all your pots. And if you've had this problem, you actually might want to soak your seeds for a minute or two in an antifungal solution. You could also use a maybe a 1 to 2 percent bleach or 5% hydrogen peroxide solution to sterilize the seeds. You're gonna want to put your soil in an oven at about 450 degrees for half an hour to 45 minutes. Sterilize your grow room. Sterilize the soil. Sterilize the seeds.
Once you have the plants growing, fungal spores are all around us, they can still get into your grow room. So some ideas to keep the damping off away are: You want to water from the bottom, don't water from the top. Never let your plants sit in standing water. Once you water them, if they don't soak all that water up in about 10 or 15 minutes, dump that out of the tray. Don't let your plants sit in standing water. Avoid overcrowding. That's one of the problems that I had here. As you can see, I have lots of little plants here and so I've watered my plants from the top, I over crowded them, and no surprise there... I have damping off.
So, to prevent damping off start with sterilized soil and seeds, water from the bottom, (and) keep air flow going to the grow room. That's (airflow is) one of the easiest things to do. If you don't have a fan in your grow room, definitely get one in there. That's going to prevent the fungus from growing. It’s also going to encourage your plants to have a better rate of photosynthesis.
So, water from the bottom, have a fan in there, avoid overcrowding, and don't let your plants sit in standing water. These are some ways that will help you to keep damping off out of your garden. Good growing!