Lettuce going thin at stem

[Marb67]

I have sown some lettuce in a tray of compost in the greenhouse as Monty Don advised now the light and heat are fading. They are not in direct sunlight and kept moist, not waterlogged. Some have come up and seem ok (though not growing that fast) but quite a few others have become thin and whispy at the base of stem and keeled over. This happened a lot last year with newly sown crops.

Any idea what this is please ?

[veggiechicken]

Sounds like Damping Off | Thompson & Morgan

[Marb67]

Spraying with a fine sprayer. One of those ones you hand pump.

[WilliamD]

Sorry Marb, you answered my question about watering, but I deleted my post as I was clearly wrong when I saw Veggiechicken's reply about damping off. She's hit the nail on the head I think.

[Scarlet]

Marb, sounds like all your pots and trays need a thorough clean and get in some new compost. Place your pots in a tray, water from the bottom, tipping the water away once the soil has had it's fill. Don't spray

[Marb67]

I did all my pots with ***** fluid this spring before i used them. I cant believe i still have this problem on top of everything else.

[Nicos]

What compost are you using?...and is it for seedlings?

The suggestion of watering from beneath is certainly the way to go.

[Marb67]

Outdoors things are watered naturally by the rain from above hence why I did this with a fine sprayer. I think the compost is a bit old and new as I have no more new left.

[Nicos]

Outdoors have more wind currents to dry out the young plants Marb..well that's what I've come to understand....and yup-I used to spray seedlings ...but don't any more.
I freely admit I am rubbish at growing from seed...or cuttings for that matter

You are using special compost for germinating seeds aren't you????...that will make a difference too.

[roitelet]

Dense sowing and overhead spraying are the two worst things for damping off. So, sow thinly with tweezers if you can, sow about twice the number of seeds than the plants you require. Soak the pots once the seeds are sown and covered and let them drain and then cover them to maintain the humidity. You shouldn't need to water until after the seeds have germinated. Once they have germinated uncover them and only water from the bottom and don't let them stand in water for any length of time.

It should work.

[bearded bloke]

As I & others have said before,diagnosing problems is a lot simpler if there are a few pictures to look at

Did Monty say which of his greenhouses he kept the seed trays in, that may have a bearing on his germination & growth rates.

[Bren In Pots]

Monty watered his Salad seeds from below :-

BBC iPlayer - Gardeners' World - 2014: Episode 20

fast-forward to around 23 to 24 minutes into the program.

[chris]

Is there anything that you can grow without problems?