Brassica Seedlings - Help!

[pippy]

I'm trying to set brassica seedlings for broccoli in modules and they are germinating okay but dying off after 2-3 weeks.  I think they may be damping off.  ???

I've not tried brassica seedlings before and have just done 2-3 seeds per section on 9 module trays.  They are in multipurpose compost - is this right?  Should I have used special potting compost or added lime?  They basically grow to the 2 leaf stage, start to form the first tiny true leaf then shrivel up.  I've tried not to overwater but it is still happening.  Also should I keep them inside or put them outside when they have germinated?

Anyone any ideas?!

[pippy]

[davyw1]

I can only tell you what i do.
I set my seeds away in trays in multipurpose compost and as soon as they a big enough to handle the seed leaf about 1" high they are potted on into potting compost in 3inch pots. I never top water, i always dip them IE i have a tray with water in it and stand the plants in it for a few minutes i judge the amount of water they have taken up by the weight of the pot
Hope this is of some help.

[tim]

How big are the modules? Shouldn't preclude a good plant if they are small - after all, all the commercial ones are from 1" plugs?

Do they collapse before shrivelling? Need water. Are the stems attacked?

[pippy]

I don't think it's the stems.  The two first leaves have just gradually turned white and then shrivelled up and died.  Then the main stem has wilted over before the "real" leaves have developed.  I have top watered them so that may be the problem then.  I also wondered if I should have firmed the compost when I planted them?  I just tap it to settle as thats what I do with Tomatoes and lettuces.

Do you firm the compost?  Some of them were transplanted but thay failed too.  I guess it's either too much water or possibly too hot as they are in a conservatory on the windowsill.  Only the weather hasn't been hot ... ???

I will try setting some more next week and water only from below. :-\

Thanks for all your help everyone.  I'll keep trying and maybe learn something!

[tim]

Join the club! This has been my worst year for germination & follow up.

No sun, but I think of 'sun scorch'? Top watering can miss the compost = dry compost & scorch?

Bash the cells on the bench? That's what I do.

But transplants? At what stage & why??

My bete noir this year is 'etoliated ' (John Wheeler?) plants which flop over, despite being in full light.

[pippy]

Thanks Tim!

I think I need to invest in some proper potting compost.  So far I've got away with multipurpose for lettuces and tomatoes, beans and herbs and sometimes some John Innes and soil mixed in for my chillies.  However I read somewhere that you shouldn't use soil based compost for brassicas - something to do with clubroot?  Maybe someone knows?

If anyone can recommend a good potting compost for brassicas please do!

[tim]

I don't think that brassicas are any different in their needs. But I DO think that some 'multi-purpose' composts are not giving a decent result in germination.

Given that yours germinate, I do not think that it's a compost problem?

[Liz W]

I've had exactly the same problem that Pippy describes. It is happening to all types of brassica seedlings, but everything else is unaffected. They start off fine, but then the seed leaves start shrivelling, and the true leaves are tiny. The same thing happened to my brassica seedlings last year. but before that I have always managed to grow them ok. I wondered if it was the compost, but I am using a different one this year and the same thing is happening. I have re-sown cabbages and sprouts, so I'll try watering from below to see if that makes a difference.

[Sinbad7]

I did a treat them mean  seed sowing of my brassica's  this year as I don't want many as I suffer with club root on my plot.  So I filled a tray with Asda compost and let it take up the water from the bottom then sowed the seeds and put a sprinkle of vermulite over them nd left them outside and within three days they had germinated and now I have about 40 very healthy plants to prick out, so no fuss has worked for me this year.  Maybe it was the quick germination thats been the secret as I haven't watered them at all as we've had a few showers between the sunshine.

Sinbad

[kt.]

Do you firm the compost?  Some of them were transplanted but they failed too.  I guess it's either too much water or possibly too hot as they are in a conservatory on the windowsill.  Only the weather hasn't been hot ... ???

I only ever use Multipurpose PB compost for everything until the plant gets in the ground, then I do not use anything.  What works for me is:

1)  Fill the seed trays with loose compost to the brim then firm this down.
2)  Water the compost a little and allow it to drain from the surface.
3)  Drop the seed onto the wet compost surface.
4)  Put enough loose compost on top of the seedling and then flatten the compost a little but not as much as the first time.
5)  Add a touch of water over the top.
6)  I water only when the top compost is very dry to touch using a light spray setting from the garden hose.  (Usually twice weekly)

[GodfreyRob]

Last year I had lots of problems with my early sowings - they would start off ok but then look like they'd been strangled from below. Brassicas went stiff and blue/purple and stopped rowing at all.

I was using some compost that I had bought 'new' in early spring but I reckon it was old stock from the previous year. I went to a different supplier and every following sowing was fine.

I have been using New Horizon organic peat free for several years and its been pretty reliable for everything.

[chilli queen]

Hi
My cabagges have done exactly the same.  I wonder if I have over watered them, but everything else planted at the same time is thriving. 

[compo49]

I started mine off in 1 inch modules in seed compost then potted them on in 3inch pots in compost from grow-bags, i bought them last year at coop(3 for £3.00) added vermiculite to it and stood them in a tray of water to wet the compost then put some vermiculite on the top to stop them damping off. Had no problems and planted early sprouts out and will be putting cabbage/caulis out soon.

[miniroots]

If the stems wither first, rather than the leaves, this is 'damping off', which is fungal.  You can treat by watering with Cheshunt Compound - but I don't really know how effective it is - I think it's a bit late by the time you spot the first visible signs...

I've had the leave withering problems that everyone discribes here - glad to know i'm not the only one.  I had thought it was maybe a day of full on the windowsill giving them a little scorch that they don't recover from...

Try again...
Mini