Damping Off - Seeds and Seedlings

VenturaHwy · Jun 7, 2018

There are a few threads on this but I like to keep it simple.

Damping Off -

Damping off is the term used for a number of different fungus-caused ailments that can kill seeds or seedlings before or after they germinate.

A seedling is perfectly healthy and a few hours later it falls over and is dead. The base of the stem is discolored or shriveled.

VenturaHwy · Jun 7, 2018

Prevention -

Tools and pots -

▪ Sterilize all used pots and trays in a solution of 10% household bleach. (one part bleach to nine parts water; soak for 30 minutes). use fresh chlorine bleach-water solutions. Don't use solutions that have sat overnight.

▪ Or in hot water (160 degrees for 30 minutes).

Soil or planting media -

▪ Use new sterilized seed starting mix. Do no reuse potting mix or use garden soil or compost. To make sure, place dampened potting mix in a microwave safe container and microwave on high for 12 - 15 minutes.

▪ Or put soil 2 to 3 inches thick in a shallow pan and heated in an oven at 180 degrees Fahrenheit for 30 minutes.

▪ Or steam (at 140°F for 30 minutes)

Seeds -

Damping-off can happen before seedlings emerge from the soil. With this type of damping-off, fungi infect seeds as they germinate. As the infection progresses, seeds rot and do not germinate, leading many home gardeners to think that the seed quality is poor. Another result of seedling infected damping-off is poor or weaker seedlings that become apparent days or weeks later.

Seed borne disease can also be avoided by soaking the seeds for 15 minutes in a bleach soak (one teaspoon per quart of water) prior to sowing.

Germinate at 78°F to 80°F in a sterile media.

VenturaHwy · Jun 7, 2018

Fungal diseases -

Pythium thrives in cool, over-wet and poorly-drained soils and is often the result of over-watering and not maintaining a warm enough soil temperature for the seeds to germinate. Its symptoms are a damp, odorless rot in the root, causing it to be slimy. It may run up the lower portion of the stem and cause it to be black and slimy. Pythium can survive in soil for several years.

Rhizoctonia is present in all natural soils, coming to life when a soil is over-wet and hot. This is the most common occurrence of damping off, as the seedling will have the classic constriction on the stem right around where it touches the soil.

Fusarium thrives in acidic soils that are poorly fertilized and can remain inactive for long periods of time – years. Fusarium infects the seeds, causing many of them to fail to germinate and creating the ‘wire-stem’ appearance in those that do survive.

VenturaHwy · Jun 7, 2018

OK that covers most of it. Here are a few more tips.

Growing seeds -

Avoid over-watering.

Air movement can significantly reduce the activity of the fungi.

Mycostop Biofungicide? It would be nice to have a seed soak that is not bleach.

A lot of times growers blame the breeder when a seed does not make it. But this disease can attack seeds before they even sprout. It seems prevention is the only thing that will work. I am also curious if older seeds are more susceptible to this?
_______________

******************* OK I tried microwaving the soil to sterilize it. What happened is it made the PH of the soil go way down. I had to flush it with a higher ph for about an hour. So microwaving your soil is really a hassle..... There must be a way to buffer the soil. And all of my 15 ph meters really suck. Not one of them is reliable. I had to go back to bromothymol blue for ph testing. Yellow is ph 6.0 and blue is 7.6. Green is about 6.5, so yellow-green is about what you need at about 6.2 ph.

DrDee · Jun 10, 2018

Nice little thread VenturaHwy,
If I may, I'd like to add a little hint that I have used for a long time. Sulfur is a natural antifungal and so I sprinkle a little powdered elemental S on the base of the seedling...on the soil, rockwool, peat or whatever. I also do this with seeds. And regarding seeds...older seeds often take longer to crack so more time to grow fungus. Never lost a seed to fungus after doing this.
JD

Hort1 · Jun 10, 2018

From time to time I have messed up and fed my seedlings high ec nutrient solution and the results are very similar to damping off.
Growth stops, stem discoloration at the base .New leaves become smaller and smaller.
I was convinced my problems were fungal but eventually realized it was nutrient burn .

stoney917 · Jun 10, 2018

Good thread ... major problem with seeds is most ppl just over feed, no food till they look hungry... also ppl start seeds in a dome n it's to humid take dome off n expect things to straighten out... no dome is best but if used u have to slowly expose them to normal humidity... good friend of mine just popped seeds got 20 of 20 took dome off and got 1 left to fast of environmental change..

DrDee · Jun 10, 2018

stoney917 said:
Good thread ... major problem with seeds is most ppl just over feed, no food till they look hungry... also ppl start seeds in a dome n it's to humid take dome off n expect things to straighten out... no dome is best but if used u have to slowly expose them to normal humidity... good friend of mine just popped seeds got 20 of 20 took dome off and got 1 left to fast of environmental change..

Stoney...I was with ya Dude until that last sentence.

So all his seeds popped but he lost 19 of the seedlings? Man that hurts.
JD

Oddvar · Sep 3, 2018

I have dampin off in my garden, i'm going to desinfect with chlorine but just in case i will grow my plants in other place and then bring Jack yo muy garden once have 20 cm...

Did damping off attacks mature plants?

Thank you!

AgentPothead · Sep 3, 2018

Oddvar said:
I have dampin off in my garden, i'm going to desinfect with chlorine but just in case i will grow my plants in other place and then bring Jack yo muy garden once have 20 cm...

Did damping off attacks mature plants?

Thank you!

Technically, yes, the same fungus attack mature plants, but it's like a baby and a grown man getting the flu. The flu can easily kill the baby, but odds are it will just make the man sick, ya know?

Oddvar · Sep 6, 2018

AgentPothead said:
Technically, yes, the same fungus attack mature plants, but it's like a baby and a grown man getting the flu. The flu can easily kill the baby, but odds are it will just make the man sick, ya know?

Thank you very much for the information, men

Oddvar · Sep 6, 2018

AgentPothead said:
Technically, yes, the same fungus attack mature plants, but it's like a baby and a grown man getting the flu. The flu can easily kill the baby, but odds are it will just make the man sick, ya know?

Thank you very much for the information, men

AgentPothead · Sep 6, 2018

Oddvar said:
Thank you very much for the information, men

Good luck and happy growing bro.

Chappi · Sep 6, 2018

I find that a heating mat and a small fan is usually enough to keep damping off away. The heat from the mat cause the water to evaporate faster and at the same time the airflow increases this too at the surface where this stuff likes to grow. I’ve had seeds damp off before without the heating mat. I feel that colder damp environment is the most prone.

TychoMonolyth · Mar 13, 2019

I had one seedling out of 50 Damp Off. It just fell over. I waited a couple days for a recovery, but it never came.

I gently pulled the seedling out of it's peat pot and starter mix, and put it in a short glass of plain water with a couple drops of h2o2 on a window sill. After about a week I noticed tiny hairs growing on the roots. I waited an extra few days and replanted it in another peat pot with the same starter mix. After a couple months, you couldn't tell it from the others.

DrDee · Mar 14, 2019

TychoMonolyth said:
I gently pulled the seedling out of it's peat pot and starter mix, and put it in a short glass of plain water with a couple drops of h2o2 on a window sill. After about a week I noticed tiny hairs growing on the roots. I waited an extra few days and replanted it in another peat pot with the same starter mix. After a couple months, you couldn't tell it from the others.

Nice save Tycho...most people wouldn't think to do that. Cheers...
JD

Lost in a SOG · Mar 14, 2019

Just use EM1.. it will outcompete the soil pathogens..

If you have bad fungus then you defonately have a lack of beneficials..

TanzanianMagic · Mar 16, 2019

To avoid damping off, it is best to sow the seed in something that has very few bacteria in it, and an environment that isn't too humid.

I prefer bagged coco coir, with a feed of 0.4 EC of bloom food which stimulates root (P) growth and strong silvery stems (K) and a little epsom salt for magnesium which keeps the leaves green and alert, and a RH of 50%. You can use a humidity dome, without spraying water, just to slow evaporation.

You can also use rockwool instead of coco coir.

And walk away.

unnamedmike · Mar 16, 2019

I live in Caribbean land surrounded by jungle, everything comes out mold. At the moment my best ratio of germinated, is using coconut sterilized in the oven 45 minutes, osmosis + hydroponic nutrients 0.8ec and 3ml/L of hydrogen peroxide. The cococoir allows to water several times a day without saturating with water, so the h2o2 reaches the roots also several times a day.

therevverend · Mar 23, 2019

I got some dirt mix, paid a bit extra for it to be organic, stuck my seeds in it. A day later the surface has mold fuzz sprouting up on it. I've got it in the house on a heat mat, if I put it outdoors in the sun the fuzz would die from the UV but it would be too cool for the seeds to quickly sprout.

No problem with dampening off, my seeds are coming up fine but this kind of thing pisses me off. Paying for a rip-off dirt mix that immediately molds. No wonder dampening off is such a common problem. It's also got the the chunks of black treated wood that hasn't broken down, the mold seems to like it. Since everyone quit growing in my area it's getting hard to find affordable grow gear.

Damping Off - Seeds and Seedlings

Active member

Active member

Active member

Active member

Member

Member

i Am SoFaKiNg WeTod DiD

Member

Active member

Just this guy, ya know?

Active member

Active member

Just this guy, ya know?

Active member

Boreal Curing

Member

GrassSnakeGenetics

Well-known member

Well-known member

Well-known member