Cabbage seedlings - some leaves wilting and curling up

[Maximus]

My wife planted some cabbage seeds a few weeks ago and they have been growing nicely.

However, we are starting to notice that some of the leaves (not all) on many of the seedlings are curling up and dying. This doesn't affect every leaf on the affected seedlings though, just one or two.

This is both happening on seedlings which she is hardening off outside (bringing them in at night) and also some which are currently sitting on a window sill which has a radiator below it (the radiator is on for a couple of hours twice a day - this is the same window sill where they germinated inside an unheated propagator.).

However, the worst affected are those which are being hardened off outside.

Neither of us have grown cabbages before so we are unsure of the cause.

The fact that those outside are worse off makes me think it's a temperature problem, but I also wonder if it's a watering issue (they do get plenty of water as they sit inside a gravel tray which has some water at the bottom).

The lower leaves are mainly affected, but sometimes just the upper leaves.

The seedlings are about 3 to 4 inches tall on average.

They are in a seed tray with a reasonable amount of space between each seedling (since they were transplanted from their tiny inserts about a week or so ago).

Thanks for any advice anyone can offer.

[Martin H]

Is it possible they are waterlogged?

[Penellype]

I find almost all brassicas will do this if they get too wet. There is a fine line between overwatering and letting them dry out, which is sometimes hard to achieve. I've taken to growing mine in self watering pots or standing on capillary matting so that they never get too wet.

[Maximus]

Thanks for the replies.

It certainly sounds possible that the compost is too wet.

My wife has been using capillary matting but perhaps we just need to moisten that
lightly ?

Is the best solution now to remove all water from the gravel tray that it's standing in and hope that the compost dries out a bit?

[Penellype]

I would certainly take the pots out of the water in the gravel tray. The idea behind the capillary matting is that it is damp and comes into contact with the compost, allowing the compost to remain damp by sucking up water from the matting without becoming waterlogged. The best way to achieve this is to dampen the matting and then put part of it in a water reservoir that is lower than the surface of the matting. If the water reservoir is higher than the matting the water will run out and flood the mat.

[Maximus]

Duly noted, many thanks for the advice.

[Scarlet]

Welcome to the vine Maximus