Sudden seedling death

[ManicComposter]

Hi all,

I wondered if you could advise me on something strange that is happening with some of my seedlings. One day they appear to be fine healthy looking seedlings, maturing and gaining strength. I could go back in an hour or two and the same seedling is bent over all flaccid.

I cannot work out why this is happening, there appears to be no damage to the plant and they haven't been watered or moved in anyway.

I'm pretty foxed.

Any help is greatly appreciated.

[ManicComposter]

[caroline7758]

Draught?

[valmarg]

Damping off would be my suggestion.

valmarg

[ManicComposter]

Draught?

They are kept in a greenhouse and the fellow seedlings in the same place seem to be fine.

[ceres]

Damping off.

[betula]

Murder?? :D

[Little Bee]

If the stems are weak at the base next to the soil then it is definitely damping off.
You may be able to save some of the ones that are not affected but you will have to act fast and prick them out into new compost into their own growing cells.
There is a product you can buy called 'chestnut compound' for damping off,you mix it with warm water and water on before sowing and during the 1st growing stages.

[ManicComposter]

I haven't watered them today and nor will I do tomorrow, none of them have died today. I will go out in the morning before I go to work and check the dampness of the soil. If it is still damp when I get back I will transplant them into new pots.

[Tyke]

I've had a lot of problems with damping off this year. Conventional advice is to water from below to prevent a build up of water on the plants and thus less fungus. However, virtually all my seedlings sown this way (with capillary matting) have died. This is about 6 trays worth in different areas of the house. Every single tray of seeds that i sowed by watering from above has survived and are flourishing. Maybe i water too much from below, but i found that the surface was bone dry and the seedlings keeled over until re-watered. I used cheshunt compound with them all....

[ManicComposter]

I've had a lot of problems with damping off this year. Conventional advice is to water from below to prevent a build up of water on the plants and thus less fungus. However, virtually all my seedlings sown this way (with capillary matting) have died. This is about 6 trays worth in different areas of the house. Every single tray of seeds that i sowed by watering from above has survived and are flourishing. Maybe i water too much from below, but i found that the surface was bone dry and the seedlings keeled over until re-watered. I used cheshunt compound with them all....

I use a spray bottle full of water to water the surfaces. This appears to work for me.
ok
I have serious problems knowing how much and when to water. Anyone have any tips?

[betula]

I always water from below,keep a close eye and as soon as the soil is moist remove from the water.

Check for the soil coming away from the side of the pot/tray this is normally a sign of the soil becoming too dry. :)

[Tyke]

Betula - Do you put the seed tray in a pot of water and then take them out when wet? I just put them on matting and water when the surface is dry - i have to put a lot of water in, but perhaps i will try your method for a while...

[betula]

The idea of watering from below is to prevent damage to your seedlings.

People have different ways of doing things,this is the method I use.

Put some water in a large bowl or sink,pop the pot/tray into the water.

The soil/compost will very quickly absorb the water from below.

Just let it get nice and damp,do not saturate.

Test soil with your finger,also look at the colour,it will go greyer,watch for soil coming away from edge,it should not reach that point.

Do not sow to close together,good air circulation is important.

A bit time consuming but worth the effort,watering very young seedlings from above can cause damage.

It is your decision but I would dump the affected seedlings and start again.

[Barnowl]

Sometimes if you touch the stem rather than the leaves of small seedlings they react by slumping over but I suppose that wouldn't explain all of them going at once.

[PurpleHeather]

Seeds planted too soon often do this. Just plant some more.

[ManicComposter]

So I came home from work to find another of my seedlings like this. I got back in my car and drove to the local garden center and bought some large trays which I can stand my seed trays and pots in.

I propose to put water into the large tray and leaving the seed trays and pots in the water. That sound feasible?

I have repotted a good 80% of my seedlings and young plants.

How much water would you add and do you recommend removing the seed trays from the water?

I have a lot of seeds in there so that probably wont be an option. The tray which I am going to add the water to is about 4 to 5cm deep I think.

Any help is greatly appreciated.

[caroline7758]

I don't think leaving the trays standing in water is good. I'mno expert (willhave to start again with someof my seeds at the weekend!) but I would say if they haven't soaked up all the water in about half an hour,you should drain the rest away if you can.

[manicscousers]

or put gravel in the bottom so the pots aren't standing in it ?

[betula]

No,You should not leave the pots in water,the compost will be much too wet. :)

[les65]

Damping off is due to several soil and water-borne fungi (particularly those in the genera Pythium, Phytophthora and Rhizoctonia) that attack the stem base, which becomes thin and brown and a white fluffy fungus may develop. The same fungi may attack below ground causing an apparent failure of seed to germinate (pre-emergence damping off). The disease is encouraged by cool, humid conditions and overwatering.

Prevention
Use clean containers, fresh compost and clean water. Sow seeds thinly. After sowing water with copper fungicide (Cheshunt Compound, Murphy Traditional Copper Fungicide).

If you use home-made compost, sterilise it before use with an electrical soil steriliser. Chemical sterilants are no longer legally available for this purpose.

Control
Remove damaged seedlings and apply a copper fungicide (Cheshunt Compound, Murphy Traditional Copper Fungicide).

i never use water from a water butt always warm fresh water from the tap for seedlings.
some seedlings will fall over from the force of the water from a watering can, but pop up again the next day.