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Cosmos plants look healthy, green and tall but no flowers yet. I have fed them with a regular general feed. Is this wrong or where have I gine wrong??



Do they have flower buds, at least?

When did you sow the seeds?

one or two flower buds, plant put out in May. Father in law grew seeds prior to May. The were about6" tall when I planted them out


If they are planted in 1. too much shade they will not flower well, or 2. too rich/good a soil they will grow bigger but at the expense of flowers. Treat them mean, dont feed, they'll eventually do their thing. J.

I put plenty of feed/nutrients into the soil as it was a new bed, in a sunny area. I shall feed no more. Thank you



mine have been terrible this year.. first year ever.. and i mean ever.. that i have not had byshy plants covered in flowers.. i dunno why.the soil and everything is the same as always.


I have had the same problem, always grown Cosmos with great results but this year they have either shrivelled up and died, or those that have lived look very sad and not flowering well at all, despite doing nothing different from previous years.  Oh well, try again next year!


yes jayne.. will always grow them.. but not so many sseeds to gather this year.. might have to buy some for next year.


I`d agree on the poor results this year, i actually pulled mine out last week, keep a close eye on them this year though as i noticed the wasps were destroying the main stem for food or nesting material


Mine have done quite well this year and have made some much needed large (4') plants in my new beds while all the new shrubs & perennials are so small. 

I sowed mine outdoors quite late (mid April I think), pinched them out a couple of times and didn't plant them out until late June. Some have been flowering well for a few weeks while a few are still in bud. I deliberately grew them this way so that they would flower later after a lot of the early - mid summer stuff has gone over.

Perhaps some of the problems people are having are with earlier sowings which may have been blighted with the prolonged cold start we had this year? The weather generally may also not have helped earlier, larger plants. Very hot and very dry then heavy rain for some. We have had some rain here but not loads & I am still watering newly planted beds on a regular basis.

On the subject of seed collecting (gardeningfanatic) - do cosmos come true from seed? I have a couple of plants which have produced particularly attractive colours or shaded petals this year - so I wondered if it was worth collecting their seed?

Mine are only just showing signs of flowering .   The leaves  dont look as healthy as usual , . a bit dry and brown patches



topbird, I collected seed from all the white cosmos in a mixed pack a couple of years ago. I was very careful to mark the white ones but I got a mix just the same.

My  conclusion is that all the colour genes are in there and you might get anything. 


This is the first time I've grown them, purity white. I got 4 small plants from a garden sale at someones house. They have all been amazing: tall with lots of flowers. Full sun and probably a bit of neglect.

My cosmos have been superb.  Flowering for 12 weeks I reckon.  I always pinch them out several times before planting out and a cut back in late spring.  For me they need good soil but no added fertiliser and not to be in the same position as the previous year.  Agree, full sun is important


Cosmos is one of those plants where you just plant in baking sun and almost forget about it. This year my Purity and Seashells have been producing the most amazing display and I havent given them any special treatment, apart from regular deadheading.




 These were taken on the 23rd August and both plants are still flowering their socks off!



Thanks nutcutlet - I'll gather some seeds from my favourite plants and see what comes up next year.

My plants are looking better now than they did even a week ago - really big and bushy. Hope they keep going for another couple of months if we don't get early frosts.


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