I haven't planted cosmos in several years. I planted the dwarf variety 3
years ago, and have just enjoyed the chance reseeding (the dwarf variety
seems to reseed a bit less prolifically than the taller varieties). This
year, I have many plants of various sizes, from 6 inches to about 2 feet
tall, all of which have been blooming for the past month or more - however,
I have one plant which has a huge healthy central stalk, numerous strong
healthy branches, and not only no flowers, but not a single flower bud. It
is about 2 1/2 feet tall by now, less than a foot from other cosmos which
have been blooming for weeks. I would say that the central stalk on the
non-blooming cosmos is nearing 2 inches in diameter, and is practically
becoming woody. Since we sometimes have a killing frost in mid-September,
I'm starting to think that I won't see a single flower off that plant. Has
anyone else had that kind of a cosmos experience?
After composting and soil improvement in my yard for the past 25 years
I can't grow cosmos either, my soil is too rich.
Cosmos prefer poor soil to bloom well- but I bet you have a ton of
I don't have the answer, but I got a cosmos just like the one you describe
in a batch I bought on closeout from a garden center. All the others in the
pack grew nicely. The one just turned into a huge bushy weed. I noticed it
seemed a bit hairier than the ones that flowered, though the leaves were
I pulled it out to give the others more room.
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I've had the same experience. One year I had cosmos plants that grew huge
but wouldn't flower. I tried adding flower fertilizer, Potassium something
I think it was, and breaking off the roots near the plant, but they would
I agree with the idea that the soil is too rich. When I first started my
garden and the soil was poor, cosmos flowered well. Now my soil is
enriched. However, the year mine wouldn't flower, I looked around the city
and saw other gardens in which the cosmos was flowering poorly, so I'm not
certain of my explanation, maybe it was just the weather.
I planted some a few years ago, they were great. I don't think they have
ever rebloomed. My job ended June 30 and I've spent more time in the
gardens this summer, and I have a ton of little plants, all 12" or less,
and no blooms. I purposely didn't weed them out thinking I'd have a mass
of colorful blooms this summer.
We do have good soil but that doesn't explain why they bloomed the first
year and never again, does it?
Diane, cosmos are annuals, so I wouldn't expect them to rebloom - only to
self-sow themselves so that a new generation could bloom the following year.
I'm wondering how you have little seedlings around if the cosmos hasn't
bloomed the past few years....
Damned if I know! Maybe I should take a pic. But they sure loke like
little Cosmos plants. I thought it was my moonbeam spreading *way* out
but they are a bit different. I think I have the good camera with me so
I'll grab a pic and send you the link later.
The pic could be cosmos foliage - it's hard to tell with the ends weighted
down with water. I suppose it's possible that some seeds survived
underground for several years and germinated when the soil was disturbed,
although I wouldn't normally think of cosmos seeds as being that persistent.
(Usually hard-coated seeds like grains and beans seem to have a longer
"shelf-life".) There are a few other plants with very fine thread-like
foliage, including nigella. Have you ever planted that? (Just thinking out
No, it doesn't sound or look familiar. Sorry, I didn't think about the
water. That area gets full souther sun against a white house and my
dryer vents nearby. However last winter was pretty hard and I almost
lost all my roses, so I would be surprised as well if they lasted
Considering it's September I guess I'll rip them out and plant real ones
next year. I really liked them.
Oh, I do have a Coreopsis Moonbeam nearby but it doesn't look *quite*
the same as that.
Any plant has the ability to re-seed, if it makes seeds. Since 'Moonbeam' is a
hybrid, it may have re-seeded, but did not have the characteristics of the
Need a good, cheap, knowledge expanding present for yourself or a friend?
I really should take another.
Anyway, it never gets more than 6" tall and is only in this one garden
(and has been).
When pulling some today I notices the bottoms of the stems were usually
I'll take some pix and start another thread.
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