Growing Cosmos from seed

[Garden Manager]

I have tried growing Cosmos bipinatus  (the annual sort) from seed this year which poor sucess.  Trouble is the seed did not come with growing instructions (free seed), so I guessed a bit on the sowing requirements. This being sown on surface of seed compost, covered with vermiculite, and placed in a heated propagator on a light windowsill.

I subsequently heard of a different method, whereby the seed tray or pot is place in a dark place until germination, as this promoted better germination. I have also seen cosmos seed in the garden centre where the intructions on the packet were near identical to the method i used - for the same species of plant!

What I would like to know is - what is the best method? Using my method I got only 2 to germinate out od around a dozen seed sown. Was i just unlucky, or did i do something wrong?

Please advise - thanks

[Garden Manager]

[Debs]

I grew my cosmos sensational mixed in a seed tray with general purpose compost, were slow at first but are now coming along nicely.

Debs

[umshamrock]

This is the second year I have grown cosmos from seed. I just put them in Jiffy 7's or multi purpose compost in a seed tray and they just grow, grow, grow. Or I sprinkle them where I want them to grow, and they grow all by themselves. I think cosmos are probably the easiest flowers to grow from seed, so give it another try (maybe you got bad seed?). Good luck!

[Garden Manager]

I think cosmos are probably the easiest flowers to grow from seed, so give it another try (maybe you got bad seed?). Good luck!

Well that gives me encouragement. Thanks.

Hmm... Maybe i DID have bad seed?!!?

[Mrs Ava]

I purchased a cosmos mix from Alan Roman and just sprinkled them in a tray and covered lightly with multi purpose compost, watered and left them on the staging in the greenhouse and they came up like cress!  Also sowed some directly on the allotment and about half of those are up also.  Betcha it was the seed Richard.

[Larkspur]

Hi, I think using a heated propagator may have been your problem. Since cosmos will germinate easily outside at this time of the year the heat may have inhibited their germination. They realy are very easy just try them in a seed tray, lightly covered. ;)

[lorna]

Well you know what a novice I am BUT I did the seed tray with all purpose compost and have had great results,(seed kindly sent to me by a member on A4A)
Very pleased.

[Gadfium]

I've also a packet of Cosmos seed from Alan Romans.

I put one seed/cell in various plant trays, watered them, and left the lot in the greenhouse. It's taken a while (12 days) but they are now beginning to appear... the last (by some way) of the various bedding seeds, which were all sown on the same day.

[MrsKP]

I'm doing a "GW" and mixing a load of seeds with some sand (including Cosmos) and just scattering it on the bed after the frosts passed.  if nothing grows i'm going after Monty with a hoe !

all my flower seeds just seem to be taking far too long in trays (lobelia, petunias) i'm wondering if it's worth all the patience and wondering if i should just go and get plug plants  ::)

;D

[Debs]

Noooo Mrs KP - much more satisfaction from growing your own - and cheaper!

Debs

[MrsKP]

i've been very good and totally ignored the plants everytime i've been to B&Q lately and i've been so lucky that the previous owner must have liked poppies as bright yellow and bright orange ones have popped up all over the place so i'm making do with those for colour till all mine show their faces.

;D

[greenstar]

I'm growing cosmos this year with seeds nicked from my mum, and scientifically stored in an old envelope on top of the kitchen cupboard.  I sowed some in seed trays on the bedroom windowsill and most of them came up so I just chucked the rest in a corner of the lottie and they all seem to be alright as well.  I'm going to be overrun with big pink daisies  :)

[fluffygrue]

Cosmos is fantastic stuff. Here it flowers til the frosts, and the hoverflies/other beasties love it. I'd recommend 'Candy Stripe' as my favourite..

And it's very easy to grow - I think you had dodgy seeds. :/

Melanie

[Garden Manager]

I've had another go with some different seed. Heres hoping.

I saw some plants at my local GC the other day going for a good price. I nearly bought some but then thought, NO, i'd rather grow my own from seedthanks and if I cant do that then they are not worth the bother!

[alit]

Hi, I didn't use heat with my cosmos seeds just normal compost covered lightly and left on staging in greenhouse 100% success.  probably have too many plants now. 

My question is when can i plant these out.  Was planning to plant out this week, then i have heard that i may be frosty and cold again for the next three weeks.    They are really getting too big for the seed tray now.

what to do!!!!!!

[Garden Manager]

Frost? Theres more chance of them getting washed away at the moment!!!

Oh, I'd leave it another week just to be sure then risk it. Have some fleece handy just in case it gets cold at night. Make sure you harden them off well in thier pots first though - put out duing the day and back in at night for a few nights.

Hope this helps