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thecuriouspeasant

Seedlings dying! Help!

Hello everyone,
I'm so discouraged! I am growing seedlings in a hoophouse and they have all been doing wonderfully! Suddenly yesterday I noticed the cucumber seedlings & canteloupe seedlings leaves had gone limp, though the stem still appeared strong and green. I thought maybe it was too hot in there for them and that the cool night would *reset* them. This morning, they had not recovered though.

Today, too, I noticed a bit of brown around the edges of some other seedlings and also around the edges of the leaves of my two tomato seedlings.

I'm thinking the problem is either: overwatering, cool nights, or too much sun/heat. If it were a fungus or virus it seems like my other beds would be suffering and they aren't.

Please, any advice! Thoughts! I want to save my seedlings!

Comments (10)

  • thecuriouspeasant
    Original Author
    9 years ago

    Tomato seedlings beginning to discolor and turn limp at top...

  • thecuriouspeasant
    Original Author
    9 years ago

    More seedling discoloration....

  • daninthedirt (USDA 9a, HZ9, CentTX, Sunset z30, Cfa)
    9 years ago

    I have to ask. Did you sterilize your planting mix? I once had problems like that, and I was told to do so. I've done it ever since, and never had any such trouble. You may just have gotten something nasty in your mix. Did you add compost?

    Also, what's in your "other beds" that aren't having this problem?

  • ltilton
    9 years ago

    They're toast. Better reseed and start over.

  • digdirt2
    9 years ago

    How often are you watering? The soil looks really wet. Over-watering kills more seedlings than anything else. I have to agree that those don't appear to be salvageable.

    And just how hot is it in there? Don't know where you live so no idea what the weather has been but here, even when it is only 50 outside if the sun is shinning it can easily be over 100 in a greenhouse without good ventilation. That can do them in within a couple of hours.

    Dave

  • thecuriouspeasant
    Original Author
    9 years ago

    The more I think about and observe this, the more I believe it really is overwatering..... though, that wouldn't explain the young tomatoes :/

    I mixed vermiculite, peat moss & composted manure to start seeds with. Everything else seems to be doing okay.

    The other raised bed, which I directly seeded is full of cold weather crops----spinach, radish, snap peas, lettuces, onions, carrots, parsley, etc -- all of which seems to be thriving...

    This post was edited by thecuriouspeasant on Thu, Apr 17, 14 at 23:25

  • Slimy_Okra
    9 years ago

    Overwatering compounded by too-cool nights can easily do them in, usually by triggering a fungal infection. That would also explain why your okra, cantaloupe and cucumber seedlings are doing the worst of all.

    I too raise seedlings in an unheated hoophouse where it gets down close to freezing at night. All the warm-weather crops have heat mats on at night and I throw on layers of floating row cover on a string support system to keep them around 60 degrees at night. The heat mats are on a timer so they turn off before sunrise.

    You're sure the manure was very well composted? Was it steer manure? Regardless of how well it was composted, manure is not recommended as a seedling potting medium because it can sometimes be high in ammonium salts. The symptoms your tomatoes are showing are somewhat reminiscent of ammonium toxicity. In the soil, bacteria quickly convert it to nitrate but these bacteria are not as abundant in containers.

    This ties in with cool nights and crop type - the combination of cold soil, high ammonium load and warmth-loving crop is a bad one.

    I would redo a potting mix and skip the manure. Substitute with compost.

    This post was edited by Slimy_Okra on Fri, Apr 18, 14 at 11:53

  • daninthedirt (USDA 9a, HZ9, CentTX, Sunset z30, Cfa)
    9 years ago

    I think that's where my question about soil sterilization came in. I guess it's easier to just avoid overwatering, but if you do overwater, or don't know how to avoid overwatering, reasonably sterile soil will help avoid infection. It's really not that hard to do that sterilization. I just bake my soil (equal parts sand, compost, and peat) for an hour (well, until the internal temp has been over 300F for a while). That does a pretty good job. Since the soil is moist when heated, it's effectively steam sterilization.

    Since I've started doing this sterilization, I've never had a problem with potted seedlings damping off.

    Of course, the seeds themselves may harbor fungal spores, and they may be deposited later by the wind, but it's a good way to be reasonably safe.

  • terry_neoh
    9 years ago

    Add some crushed dolomotic limestone (agricultural lime) with your potting mix. This will help neutrilize the soil if it is too acid, and it will add magnesium.

    Many plants, especially solanaceae (tomatoe, peppers, potatoes, eggplant) need magnesium to form chlorophyll (the green stuff in plants). It, quite literally, can't hurt.

  • thecuriouspeasant
    Original Author
    9 years ago

    Slimy Okra I think you're spot on when you say:

    "Overwatering compounded by too-cool nights can easily do them in, usually by triggering a fungal infection. That would also explain why your okra, cantaloupe and cucumber seedlings are doing the worst of all."

    I *think* this is what has happened. Everything else seems to be doing splendidly! Well darn, I was quite fond of those heirloom tomatoes. Guess I'll just start more seeds this weekend. You live, you learn.

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