Trouble with tiny seedlings
April 2, 2012 2:49 PM Subscribe
I'm growing plants indoors in pots for transferring outside later, and some of them aren't doing as well as others.
The tinier seedlings are doing this thing where they shoot up an inch or two, then the based shrivels up and it falls over dead. They don't all do it, appears to be about half of all seedlings, and it's only the really thin plants (poppies, lettuce, mustard) that are doing it.
I'm careful about not over watering (I've had the soil dry up a few times), and I don't think they are drying out or else they'd all fall over. Would a starter fertilizer help? Could this be a nutritional problem?
The tinier seedlings are doing this thing where they shoot up an inch or two, then the based shrivels up and it falls over dead. They don't all do it, appears to be about half of all seedlings, and it's only the really thin plants (poppies, lettuce, mustard) that are doing it.
I'm careful about not over watering (I've had the soil dry up a few times), and I don't think they are drying out or else they'd all fall over. Would a starter fertilizer help? Could this be a nutritional problem?
It might be damping off. This is hard to treat once it becomes an issue, unfortunately. It's best to prevent it by using sterile potting mix, and good air circulation.
posted by Ostara at 2:57 PM on April 2, 2012 [1 favorite]
posted by Ostara at 2:57 PM on April 2, 2012 [1 favorite]
Yeah, damping off. You are probably going to have to start over, this time bleach all your pots and use sterile potting mix.
posted by fshgrl at 3:08 PM on April 2, 2012
posted by fshgrl at 3:08 PM on April 2, 2012
How much light are they getting, and is it good quality light?
posted by gjc at 3:38 PM on April 2, 2012
posted by gjc at 3:38 PM on April 2, 2012
Sounds like damping off. I had similar problems which I was told by a gardening friend was caused by not enough light, I've managed to save about half the seedlings I planted by taking them outside everyday into the sun as I can't afford a light for them all this year. I planted a second batch of seeds in the same sort of pots etc the only difference is being outside from morning until night and only one seedling got damping off instead of me loosing over half. You have to throw out any plants afflicted with it as it can spread.
If you are using lights you might want to lower them closer to the plants.
posted by wwax at 3:52 PM on April 2, 2012
If you are using lights you might want to lower them closer to the plants.
posted by wwax at 3:52 PM on April 2, 2012
Response by poster: Light could definitely be the issue, they don't get a lot of direct light. If I were to buy a bulb to help, what would be best? (and affordable).
posted by Dynex at 3:57 PM on April 2, 2012
posted by Dynex at 3:57 PM on April 2, 2012
A regular fluorescent shop light will work for this purpose, but you need to rig it to hang way closer to the plants than you might think - within an inch or two of their tops. Here's an example of how to do it.
posted by jocelmeow at 4:57 PM on April 2, 2012
posted by jocelmeow at 4:57 PM on April 2, 2012
Response by poster: I'm not able to hang anything. I'm probably going to turn two lamps on over them, are the bulbs already in the lamps suitable?
posted by Dynex at 5:06 PM on April 2, 2012
posted by Dynex at 5:06 PM on April 2, 2012
Fluorescent bulbs are better than incandescent both light- and heat-wise. Incandescents put out a lot more heat and can fry the plants, and if you put the light far back to avoid that, it isn't providing enough lumens. Full/daylight spectrum fluorescents are better than not. If you're serious about growing these plants, I'd invest the extra $5/bulb or so on getting daylight spectrum fluorescent bulbs.
posted by vegartanipla at 5:11 PM on April 2, 2012
posted by vegartanipla at 5:11 PM on April 2, 2012
Lack of light would not be causing the base to shrivel and the seedlings to fall over. As several people upthread mentioned, this is textbook damping off.
posted by oneirodynia at 5:28 PM on April 2, 2012
posted by oneirodynia at 5:28 PM on April 2, 2012
Best answer: Lack of light would not, indeed, be causing the base to shrivel. But it can cause them to fall over. It sounds to me like you might have several issues going on -- damping off, lack of light, lack of water.
You want to keep a light just a couple-few inches from the seedlings' leaves for a good while. Seedlings getting tall and then falling over (with no other signs) means they were trying so hard to reach the light that they grew tall before they grew stout, and the stem couldn't support the height. Nothing should be "shooting up."
Here are a couple of good resources based on a very perfunctory search on You Grow Girl:
how to build a DIY lighting system
Starting healthy tomatoes
Others are right, too, that you shouldn't be letting the soil dry out. Especially if they are still germinating, if the tiny little root hairs dry out when they are still tender little babies, your seedling is basically lost. Additionally, with some seeds (parsnips in particular come to mind, not sure about flower varieties), if the soil surface dries out and forms a crust, they'll never be able to break through it.
posted by librarina at 9:04 PM on April 2, 2012 [1 favorite]
You want to keep a light just a couple-few inches from the seedlings' leaves for a good while. Seedlings getting tall and then falling over (with no other signs) means they were trying so hard to reach the light that they grew tall before they grew stout, and the stem couldn't support the height. Nothing should be "shooting up."
Here are a couple of good resources based on a very perfunctory search on You Grow Girl:
how to build a DIY lighting system
Starting healthy tomatoes
Others are right, too, that you shouldn't be letting the soil dry out. Especially if they are still germinating, if the tiny little root hairs dry out when they are still tender little babies, your seedling is basically lost. Additionally, with some seeds (parsnips in particular come to mind, not sure about flower varieties), if the soil surface dries out and forms a crust, they'll never be able to break through it.
posted by librarina at 9:04 PM on April 2, 2012 [1 favorite]
Response by poster: Thanks all, I'm trying more light and a touch more water. Last year I lost a ton of seedlings to mold so this year I was using less water and have a fan on them. If it is damping then I am fresh out of ideas (this is all brand new soil and containers, so not contaminated from last year).
posted by Dynex at 9:24 PM on April 3, 2012
posted by Dynex at 9:24 PM on April 3, 2012
This thread is closed to new comments.
posted by myselfasme at 2:54 PM on April 2, 2012