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Hi, Is  it possible to keep Cosmos from year to year or is it purely an annual.  Have grown them for the first time this year and would love to keep them for next year, but wonder if it is best to start from scratch next year.

I believe you can get the seeds from them and grow them on for the following year, have not done it myself but going to try this year, so fingers crossed.

Only the chocolate osmos is perennial. The best cosmos comes from fresh seed each year. Not expensive are they?
Leggi

Check your plant for it's prettiest flower and tie a small bit of string around the stem (if you want more than one flower to set seed you can do this to as many as you like) deadhead the plant as normal so it keeps flowering. When the plants begin to die off in autumn your selected flower heads will have turned in to seed heads, pick them off and store in paper bags over winter and you'll have your seeds for sowing in spring, you can then dig up the plant and compost it (or get rid however you usually do).

I do this every year but I also buy new seeds to mix in (59p from Morrisons this year), I just love Cosmos far too much!

Jean Genie

Leggi - will this work for all cosmos ? I've been missing out !

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Leggi

If it's an annual cosmos I can't see why not, I also do the same with sunflowers, poppies, red flax, annual chrysanthemum and Verbena Bonariensis (and probably some others I've forgotten)

Johnboy2

I tried the Double click cranberry and sea shells mixture this year and I'm so glad I did.  What fantastic plants they are and i hope they will go on for a lot longer.  Some of the plants have only just started flowering. You have to try the double click Cranberry ones though...they are stunning.

 

Jean Genie

Johnboy - I've just googled Double click cranberry cosmos and it is now on my shopping list ! Thanks for that - I've grown seashells . Just love the fluted petals .

Jean Genie

Sorry Leggi - thanks for your advice , I shall be wandering around the garden with a full set of paper bags come Autumn !

budlia63

i love these little gems i bought them outside my local asian grocers last year. this year i have grown my own and the display is even better. next year i will try my own seeds. great advice here 

Thanks Leggi, I shall certainly try to grow them from seed.  There is a lovely deep maroonie colour which I would love for next year, so will certainly try to save the seed.  I presume you sow the seed in spring for planting out early summer?

Leggi

Yes from late feburary, I start mine off on a sunny windowsil in seed trays in gritty compost. Prick them out when they have their first true leaves (you'll know what Cosmos leaves should look like) pot on to 5cm pots and off they go outside to the propagator, then pot them on again to 10cm pots until they're big enough to grow in the ground around April.

You can sow Cosmos directly in to the ground as well, although I'm not much of a fan of that as the seedlings are tasty to slugs, snails and mice. If you want to do this though it should work, just sow more seeds than you think is necessary.

I grow pure white ones, seashells and the maroon ones you've mentioned this way.

Atilla

As mentioned Cosmos are annual. I have seen them grow in Africa and in their homeland, Mexico. They grow to large 6ft bushes over there, but die down every year. In the UK you collect the seed heads and get more to grow next year - they are pretty easy to germiniate. They also self seed though my ones this year are just about to flower.

 

hollie hock

Hello, I've just started collecting seeds to sow for next year. For me, collecting seeds from annuals are not  worth the effort, unless you  have the space and time  to grow them on/ or live in mild weather conditons. The seeds are really cheap. Ive been growing Cosmos Purity.,. did very badly in the lack of Summer.

Jean- there's loads of seeds to be collected in the garden. I still haven't cut my foxgloves off.

budlia63

just a note to add I stook a couple of broken cosmos around the edge of a plastic pot about a fortnight ago. today i needed the pot so dug them out and they had loads of little white roots around the base of stems.  i was thinking that nest year when growing seeeds is it worth taking some stem cuttins from strong plants to make more?

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budlia63


now i can i thought i'd share a pic anyone got any more b interested to look at good companions

hollie hock

Cosmos are lovely flowers- I've been growing the Purity ones for the first time this year.

Interesting what you said about the white roots. One of mine got really battered earlier this year and the stem was badly bent- the plant was still alive so I just left it resting on the ground.Just by chance I picked up the stem the other day and there are loads of roots coming out of the stem that was on the ground. So I guess it is possibly to take stem cuttings

Purity seem to be a popular one so will look for some to sow next year.  I will also try doing stem cutting and see what happens.  Thanks for the tip.

They are a lovely flower to grow on the alloment and the bees just love them. They will sometimes happily set seed but it is lovely trying out new varieties from the seed people. Also a lovely cut flower especially for the annual seed category in the horticultural show. I find they grow much taller on there as they have plenty of space and dont have to compete with all the other flowers.

This year I had a couple of double white cosmos from seed of purity. Really lovely. Unusual?