Damping Off Help Needed

[MuddyBuckets]

zipcode

Guilty again, I have always set seedlings deeper when up-potting. Will alter this on some of the newer seedlings and see if it helps.

[b54red]

You can do everything right and still get damping off down here where the stuff is even in the air. I found one thing that helps more than anything else that I have tried and that is using DE for a seed starting medium. It has a couple of real advantages it is sterile and the surface dries fast. It has a couple of disadvantages also. It must be bottom watered early on and it has no nutrients so the seedlings must be fertilized shortly after popping up.

Using DE as a starting medium on small seeds has cut my damping off incidences by 90%. Even so this winter has been tough stopping damping off due to the constant rain, cold damp nights, and terribly low light levels in the greenhouse for well over half the time the past two months. Watering only when the medium is dry and plants wilting has not totally controlled it even in the sterile medium due to the fact that sometimes after watering the DE remains too wet due to the 100% humidity and cool conditions. This has been the worst winter for damping off that I have experienced since I started using DE as a seed starting medium but it is still better than a normal winter with more common seed starting mediums.

Bill

[oakley]

I snap cell phone pics near daily.

When I see any issues, I immediately start a new tray....new fresh soiless mix. I may keep the troubled seedlings in case they recover but often not worth it.

Around thanksgiving I start a 1010 36 cell tray for soil and seed germination testing.
My own saved seed, one per cell, 12 cells of saved pepper seed. I use a seed map so no need
to make individual markers. Quick trial and onto a heat mat.

I'm testing the exact soiless mix I'll be using. I had good germination and up as expected.

A couple weeks later I started a 1010 tray of micro F2's for hunting.
When I fed the previously started tray very dilute, I went ahead and fed the micros.
Bad idea. Their growth was stunted. I knew the issue within a week. Out they went into the
deck snow bank. Not worth trying to save. (plenty of seed)

2017 I had horrid dampening off due to crap soil. I sterilized it in the oven but it was clearly
old stock and had broken down so much it became rock solid like clay in my trays.
2018 I had a mold issue due to so much Spring rain and high humidity in my seed starting
room.
Both years I started back-up trays in my kitchen pantry. They did excellent.

So,... take pics, Like Karen wants to see, (I agree), and have a back-up plan so your growing
season will not suffer. Sick looking suffering seedlings often struggle to recover.

[oakley]

Here is a pic from a couple days ago. I labeled it 'first potting up 2.20.2020'
I'll pot up another dozen tomorrow. Started another tray this morning of Dwarfs.

After 2017 and 8, decided not to struggle with sickness. Do-overs. If a seed tray looks
good, they move forward...
These are tall pots. 3/4 full. The only time I top water is immediately after potting up.
Takes out all soil air pockets. I'll add more soil in a couple weeks.

[KarenO]

Originally Posted by MuddyBuckets

KarenO

Here a couple of pics, larger tom is a ColdSet Dwarf (sprouted mid December and potted up in early February) and smaller is Fire Marzano Roma sprouted early January.

Ok, they are both very stunted and small for their age but the Marzano fire looks alright just small. What are they growing in? Have they been in good light and a warm area? I would expect a seedling planted mid December to be budding by now in my house. It’s a sad thing to say but I recommend a do-over with new specifically formulated seedling mix and either new or soaked and scrubbed in soapy bleach water and rinsed. with a thoroughly cleaned planting area. fusarium is one of the organisms that can cause damping off and I’m concerned it could be wilt.
Seedlings that are growing fast and well in good conditions can have a chance to fight off or outgrow infection but slow growing cold wet seedlings really can’t and even survivors are unlikely to do well for you despite your best efforts.

In illustration, this photo is of seedlings sown at the end of January and are growing fast as I would expect in my house under lights. Sown in seedling mix and potted up now to individual pots up to their first set of leaves. I think you will have better luck with the next ones.

[MuddyBuckets]

At what stage do you typically pot up? When there are 2 real leaves? When there are 4 real leaves? When it gets too leggy? Mine growing close to the LED lights still get very leggy early in development and I pot them up at about 2" with a second set of true leaves.

[KarenO]

Yes generally around the time they are getting their second set of leaves.
I use fluorescent tubes in front of a big south window. Normal room temp about 70. Air is fairly dry in my house in winter, humidity around 30%. I do Nothing fancy.
KarenO

[zipcode]

Originally Posted by MuddyBuckets

Mine growing close to the LED lights still get very leggy early in development and I pot them up at about 2" with a second set of true leaves.

2 sets of leaves at 2 inch sounds ok, but if you think they are leggy then it's probably not enough light.

[habitat_gardener]

I went to a workshop on succulent propagation last week at the local arboretum. One thing they do for slow-growing seeds is to water in with straight hydrogen peroxide (but said it has been shown to be just as effective 1:3). They also put a layer of #12 sand on top of the seeds, rather than having any organics on the soil surface. This discourages fungus gnats.

For slow growers, the seeds are potted up, watered in, then placed in a ziplock bag until the seeds germinate (so that they stay moist, and don't have to be watered again). Once the seeds germinate, the bag is slowly opened over a couple weeks -- a crack, folded back, etc. -- so that the moisture levels don't change suddenly.

I wonder if they hydrogen peroxide watering and the mineral layer on top might help with damping off.

[Fusion_power]

I wonder if they hydrogen peroxide watering and the mineral layer on top might help with damping off.

No. Damping off is almost always fungal in origin and either starts with contaminated media or comes from conditions ideal to fungal growth, i.e. cool, moist, with low light levels. I have seen it start from seed where only 1 cell in a tray of 18 had a problem. The media was the same, the watering was the same, the light and temperature were the same. The only difference was that seed of one particular variety carried enough fungal spores to start the sequence leading to dead seedlings. I washed the seed in bleach for 5 minutes and voila, the next batch of seed germinated and grew with no issues.


I have posted in the past about using hydrogen peroxide to enhance germination of very old seed. It is very useful when working with seed and plants.