Topic: Brassica seedlings cotyledons turning yellow

[Digeroo]

Can anyone tell me why my brassica seedlings are turning yellow.

The odd thing is that only half of them have the problem.  So this seems to be a problem with only one variety of seeds.

Had I only sown one variety I would have blamed all sorts of things compost, watering, temperature etc etc.  But I fail to understand why one variety should have a problem and not another.  They were both F1 hybrid seeds.  Now one set of seedling are four times the size of the others but actually the first were the first to germinate and were fine to start with.

Can anyone shed any like on this?

[saddad]

Have they put out any true leaves yet?  :-\

[Pescador]

Hi Digeroo,
I've got exactly the same problem. Greyhound and Primo have grown away fine, but Kale and Cauli are stunted with yellow cotyledons.
Sown same day, same compost, same temperatures etc.
All new seed as well.
Any ideas?

[manicscousers]

anyone using peat pots?
I had this problem last year with them

[Dandytown]

Used peat pots for all of mine, cauli, broc and bruss and no problem with them

[manicscousers]

I think mine were the cheap ones  :-\

[chriscross1966]

wrong variety for the time of year? Brassicas can be unforgiving about that sort of thing.....

[Robert_Brenchley]

I won't be planting kale till next month, when it'll be warmer and they'll get more sunlight. What cauli is it? I've put a few All the Year Round in, but if they don't work I don't mind, as I've got loads of seeds, and can replant next month.

[Pescador]

Cauli are AYR, have to check on the Kale

[Digeroo]

One batch Calebrese Lord from Sluis - doing very well.  Two good true leaves per plant and another two just peeking through plus two colyledons.  One batch Unwins Green Magic (says on packet to sow indoor in Feb) two very small miserable true leaves and now completely curled up colyledons and plants looking poor, some will not survive.  Same compost, same yogurt pots, same water, same windowsill, same orientation to the sun, same spread of distance from the window etc etc.  There are twenty of them in the same box.  Green Magic germinated first and looked the best to start with, but now Lord are ten times the size.   All F1 hybrids. 

[Robert_Brenchley]

Cauli are AYR, have to check on the Kale

My All the Year Round are looking healthy so far.

[Digeroo]

Sounds a good idea to give them a feed anyway.  Many thanks for your suggestions.  They have just had a high nitrogen liquid feed.  Lets hope that does the trick.

Maybe one set of seeds was slightly bigger and so had a better supply of nutrients on board.

It is very annoying to buy expensive seed compost only to find it maybe lacking in nutrients.  I wll do another batch of each on some organic quality leaf mould and see what happens. 

[aj]

It is very annoying to buy expensive seed compost only to find it maybe lacking in nutrients.  I wll do another batch of each on some organic quality leaf mould and see what happens. 

Seed composts are supposed to be low in nutrients. Once out of the 'seed' - they need to be potted on into multipurpose.

[Digeroo]

Well a big thank you to A4A and especially the person who PM with the solution.  After a good high nitrogren feed I threw them out into the allotment.  And after a while they suddenly took off.

I have just picked a 4 inch size brocolli head and very pleased with it indeed.  My first large head ever.  I now have another 15 so in the next couple of weeks I will look like calabrese.

They were in multipurpose but obviously not enough nutrient in it.  In the end mixed in recycled compost for other things and that is much better.