Seedling composts

Hiya,

I was wondering what you all do when growing plants from seed. I have John Innes seedling compost for germinating the seeds in.

Do I then prick and pot on the new seedlings (generally) into more of this compost when they are large enough? Or is best to quickly move onto something with more nutrients? Like a No.1?

I.e. Step 1) propagator with seed compost, Step 2) pot on to 10 cm pot with more seed compost, Step 3) pot onto larger 15 - 20 cm pot with John Innes no.1.

Or is it at Step 2 that I should be using John Innes no.1?

I'm getting ready for the big Feb plant up and want to make sure I get everything right this time :D

Jack

 

Hi Jack,
I make up my own mix depending what seeds I am growing, and my month to start is normally March otherwise if a late spring I just run out of room in the greenhouse and windowsills !

• John inns no 1 50%
• perlite 20%
• 20 % multi purpose
• 10 % sharp sand

If seeds need light to germinate I crush perlite in my hand and sprinkle over the seeds, I tend to grow most things in modules just makes it easier for me as some seedlings are very fiddly (ie lobelia) and I only use the seed amount I want, plus side with the mix I use keeps them going for 6 weeks before I need to do anything else with them , but with french Marigold which I grow at least 4 varieties they go into trays as they are so easy to split and transplant.

With daylily seeds they get planted November/December in a plastic takeaway container with damp vermiculite in then the lid put on and then kept in the fridge until they start to sprout then they go in the mix above into the greenhouse and I have done the same with lavender.

Always amazes me that some seeds need to be chilled to get them to grow.

Spruce

 

I find seed composts too prone to compaction.

Make my own up with 75% sieved garden compost and 25% vermiculite.

 

Hi Zig

Do you sterlise the compost in the microwave ?

 

I'd have a job to do that, struggling to get enough electric to power the laptop at this time of year

 

More and more of my sowing is being done in cotton wool and placcy bags............


They're then hung here for those that need heat..............


However for fine seed compost is best. I just use Humax original MPC that I pour boiling water through (in the pot) and then dry off in the microwave.

http://www.gro-welldirect.co.uk/gro...umax-original-formulation-multipurpose-60ltr/

It's really good MPC and I just pot on into that, although I may add sand and/or perlite depending. So (for example) for fine seedlings I add perlite, bulbous pant seedlings both and something like Canna I add nothing.

 

You're making me wish I had much more space - I'm gardening on a micro scale :D I have one windowsill propagator and one small lightbox and that's about it.

I think the mix you mention Spruce makes sense.

I seem to be able to get most seeds to germinate, it's what happens next where I struggle as they seem to just stop at after the first couple of sets of leaves. Admittedly, I didn't have the light box before which worked well with the lettuce I tried until they all got some kind of fungal problem.

I just wondered if it might be the lack of nutrients in the compost that's stopping them growing on.

 

At what point are you pricking them out?

 

Once they have one or two sets of true leaves.

 

+quote is not working for me on this thread, but 'reply' does.

I only find that with JI composts, so either use 100% of non-JI, or mix 50:50 with other, quality stuff, especially for seeds that I've found to grow better (healthier root system) in a partial JI mix.

 

Only ever tried JI seed compost, it put me off buying them.

 

I hate it because it can 'cake' solid and I believe if suffacates seeds. That's why I bought 15 bags of this stuff
http://gardenerscorner.co.uk/forum/threads/20l-westland-seed-compost-75p-tesco.87990/

 

I agree with Zigs and Scrungee for the same reasons. I wonder if they're stalling and keeling over as a result of root damage (for the reason above not as a result of your technique).
Personally I prefer to prick out straight after germination.

 

I use the Westland seed compost as Scrungee linked or the B and Q verve seed compost . I mix about 25% perlite with it sometimes . I have tried top watering and bottom watering , both difficult to control for seedlings . I now wet ,to the correct amount ,the compost perlite mix in my mixing tray and then fill the seed propagators and tamp down . If the seeds are surface sown I put a thin layer off vermiculite over them and lightly spray with a copper solution ( no Cheshunt these days !) This seems to work fine the seed compost is nice and airy and not over watered . I do bottom water if the seedlings need watering after sprouting , but I do this carefully.
I prick out when the true leaves have formed into normal MPC.

 

I think lack of warmth if they just stop at two leaves and with just John ins soil it can hold too much water thats why I use my mix most of the time