Mine got so big last year that I had to rip half out. And it wasn't easy, they were just as you described, big stems and a root system beyond. They did bloom well and had many people stop to say they had never seen so many this big before.

I didn't plant any this year in the same place because of the rampant growth, but have a few that found their way from seeds of last. These are about 4' high and budding. Knowing we both love them, I know there are different species and wonder if we just happened upon a very large one. Or our soil is so rich they became rich too. Last year was also very rainy, this year a drought.

I love the bright orange, 6" high cosmos too. They never fail me. But our giant ones are certainly not the norm from years of experience.

I'm glad yours at least bloomed! I don't think I'd mind so much if mine bloomed. So far this year I have one bloom on the tallest of the plants, which is a bit over 5 feet. None of the others even has any buds.
Maybe I'll try ordering from a different source next year. (The last 2 years I've ordered from a new-to-me company, Territorial. All their other seeds have been fine.) I'll plant them in the BACK of the beds instead in front. But with my luck they'll turn out to be the normal 2.5-3 feet tall!
Thanks for responding. I'm really curious to find out if many other people have experienced this.

I've never been on this site before. I recognized thinman who also posts on the Cottage Garden Forum that I am a part of.

I have a new bed that I started the first week of June. I planted 2 kinds of cosmos from purchased plants. The white flowering ones from the nursery that grows their own, have been blooming, but are not getting very big, about a foot. One is 2 feet. The others were purchased from a plant stand at a local pharmacy. They are supposed to be mixed colors. They are huge, about 4 to 5 feet, and I have had 2 white flowers so far. I would like to find some old fashioned seed and see if that makes a difference. I think some of the hybridization isn't necessarily making improvements.

Sue

Sulphur Cosmos up-date. Out of 16 plants, only two are blooming, and the others have no buds at all. They are all huge. Monstrously huge!
lvtgrdn, I think you're talking about the Sensation type of cosmos. They come in dwarf and taller varieties. The tall ones do get 5 or 6 feet tall, and are white, pink, and a kind of dark purple. They're very easy to grow from seed and just about every catalog offers a variety. The sulphur cosmos, variety Bright Lights, have a completely different leaf and flower, and the blooms are yellow, orange, and dark orange. They're supposed to grow about 2.5 to 3 feet tall.

Do you save seeds? I wonder if you've unintentionally selected a progenitor that is daylength sensitive, and is "waiting" until the autumnn equinox to flower. I have some marigolds from Africa that do the same.

I used to save seeds, but for the last few years have not been. The last 2 years I've planted fresh, newly purchased seed. That's an interesting theory. Maybe the seed company has unintentionally selected a daylight sensitive progenitor.
Now I'm wishing I'd saved seed 3 years ago!

Hi weld,
I'll send you some of my seed.
I have two varieties: "Bright Lights" have reverted mostly to a golden color, and "sulphureus" are vivid clear yellow, orange, and almost red. I already have seed from "Bright Lights" collected. Email me if you are interested.
Renee

Thanks so much, Renee!
A friend of mine says she can give me lots of seed this fall. Kind of nice, since she's still growing cosmos from seed I gave her years ago. It will be interesting to see what develops.
Thanks again for your kind offer.

Weld,

Would you mind sharing with us where you purchased your seeds or the brand of seeds?

Teresa

I decided about two years ago not to use them in bouquets any more - or at least not to rely on them for bouquets, because they seem very fragile. But I still wanted to grow them for my own enjoyment.

However, for the last two years, they have not bloomed. It's a good thing I *didn't* rely on them!

:)
Dee

Hi all, I grew Versailles mix this year and loved it. The colors are clear in light and dark pinks and the stems are strong and have a good 18" of straight stem to cut, high bud count and good bloom on cut stems. I'll grow these again, of course, it doesnt answer the orange and yellow question. Kat

The last 2 years I've bought Bright Light Cosmos from Territorial Seed, and this is the first time I've purchased from them. (All their other seed has been very good.) I had been hoping the problem is only with this one source, but I think it's probably more widespread than that given the number of people who have mentioned unusual sulphur cosmos in recent years.

Hi All - I kind of ignored this thread, because years ago I grew the brigt lights and they were too timeconsuming to cut and didn't get the stem length I wanted.

I do grow the Sensation series (white, pink and tall especially if you pinch them at around 1'), Red Versaille, Candy Stripe, sometimes the new double one (can't remember its name). Seashells bloom too late.

And, I did grow a pale, beautiful yellow up until two years ago. It got over 6' tall BEFORE it bloomed! It was a great fall flower, if it didn't frost first! Tons of blooms for the space it took. But, I noticed Gloeckner and others aren't carrying the seed any longer. I think it was Campus Yellow (there may still be a thread on this subject out on the forum somewhere). I decided that I need to think about winterizing the field earlier than these bloom, so have removed them from my list of flowers to grow!

I suspect that's the variety you all ended up with!
Wendy

Here's a link to the old thread!

Here is a link that might be useful: Yellow cosmos

Thanks for the link, Wendy. I tried searching for campus yellow and they look the same as the gold "bright lights" in the photos. Also tried finding the apricot color, but no luck! If anyone finds either a pale yellow or an apricot, I would be very grateful for the link.
Renee

Tons of blooms for the space it took up? And pale yellow? Nope, that's not what I've got. These plants are 4-5 feet in diameter, the 2 that have bloomed are orange, not the mix of color I'm used to. Just imagine 14 plants that are between 3 to 5 feet in diameter (2 comparatively small ones are 3 feet in diameter) not blooming, taking up valuable space and valuable nutrients in my garden. Tomorrow I'll rip out the 14 to make room for fall planting. If last year was any indication, all I'd get, a day or two before frost, is 5 blooms from these remaining 14. Not at all worth it.

I'm very bad at estimating size. I'd say my cosmos are more like 3 feet in diameter on average, the smaller ones 2.

Last update for the year, I promise. (I'm a bit obsessed, I see.)

Anyway, I did not yank out the 14 non-blooming huge sulphur cosmos when I said I was going to. Thought that in the interests of "science" I should give them a bit more time, see if they were EVER going to bloom. As of today, none of the 14 has bloomed, and I have indeed removed them. They are difficult to dislodge, and I'm going to have to go back and use a shovel to remove the root balls and stem stubs I was unable to pull up by hand.

Mine have not yet bloomed either. The plants look great and healthy, but *still* no blooms. I don't understand - the first year or two, they were so beautiful, and then... nothing.

I hope mine are not as difficult to pull up as yours were!

:)
Dee

Well, I actually noticed a bloom today! Although, to be honest, after looking more closely, I'm not so sure this particular bloom was Bright Lights after all. It was a bit paler yellow in color.

At that point, I remembered that I had sown some Yellow Garden cosmos, so perhaps I mixed them in with the Bright Lights, since I didn't have spectacular germination with either this year.

I did notice lots and lots of buds on the rest of the cosmos. Hope they have time to bloom!

:)
Dee

P.S. My pink, white, and magenta cosmos are absolutely spectacular at the moment!

In searching my history of planting seasons past, I came across a note to self regarding Cosmos "Polidor". I remember that this cosmos was absolutely gorgeous, bi-colored orange and yellow flowers, very well branched and a good producer. Height approx 4 - 5 feet. Blooming from the end of July onwards here in S. Oregon. Hope this helps. Seed is available from Thompson and Morgan.
Kat

Kat, thanks for that info on Polidor. I've seen this variety in catalogs, but never got it because I had the Bright Lights seeds. Maybe I'll give the Polidor a try since it blooms so much earlier (although in the past, the Bright Lights bloomed a lot earlier for me too. Go figure...).

Thanks!
Dee

Hi,
I grew the Bright Light Cosmos for the first time this year and like many of the previous posters, was very disappointed in their growth and blooming characteristics. The seeds were planted in a newly rototilled bed which was enriched with compost and a little 10-10-10. These Cosmos were monster plants reaching over 6 feet tall and several feet wide. I realize that the fertilizer could have contributed to the excessive growth of the plants. However, some of the plants produced many blooms and some plants did not bloom at all.

I was hoping to use the flowers in bouquets, but I found that the cut flowers did not last more than a few days before falling apart. Meanwhile, the plants that did bloom dropped seeds all over and within a short period of time, the seeds had sprouted like weeds in the garden paths. Within a short period of time, the self-seeded plants had grown about 2 feet tall and were blooming.

I love Cosmos, but I won't grow the Bright Lights again.

I'm glad to see that I'm not the only one who gets 5 - 6ft of height from this plant. I'd had Cosmos for two years before I switched locations from a part-shade spot to a full sun spot. It grew very sparsely, but bloomed nicely, in partial shade and only to a height of about 1 -1 1/2 feet. I have Bright Lights and saved seed from '07. Last year, I was 'shocked' at the difference it showed in full sun. (At least I thought that was the difference.) ..It grew taller than me and had very thick stalks. Also, there was continuous blooming from early summer into fall. I'm growing it again this year, using last year's ('08) seed ..in a different full sun location. I almost decided not to grow it again this year because it became so thick. ..I'll see how it goes this time around. (Maybe it was the weather combo we experienced last year.) ..Also..it attracts Hummingbirds. ..Who knew!

I had yellow cosmos growing,they grew to about 4ft r so. This year I purchased some "Bright lights" from Parks Seed. I grew 10 plants. Of those 3 started blooming at the end of May. They are all very large and the blooming ones are beautiful. However the other 7 are just taking up space. I wonder should I save the seeds from the blooming ones to plant next year, or just give it up and let the shorter, better blooming ones reseed. Definitaly a big disapointment.

Hmm. That's very interesting. I'll try Parks next year. Blooming at the end of May would be early for me. I'd say don't give up on the others quite yet, and YES save seed from the ones that are successful!

This year I tried a new-to-me type, Sunshine, from Johnny's seeds. They're doing great, blooming away, but I failed to notice they only get 12-15 inches high. Also they don't hold the blooms high up above the plant like Bright Lights used to do.....one of their most charming qualities, in my opinion. Half of these blooms seem buried in the foliage.

Thanks for mentioning Park's. I would really love to find a source for the old Bright Lights I loved for years.
I loved that airiness.

I was wondering if any one has expirenced nutrient deficiencies or toxicity problems while growing cosmos in pots. They are the Gazebo mix from parks seed. They are growing rapidly but the older leaves lower on the stem are curling towards the stem. This is my first time growing them and I'm not quite sure what they are suppose to look like after a month of growth

I've had the exact problem in SW PA. I planted some of the same seeds in a container vs. the ground and they are rather spindly. The seeds planted in full sun are very bushy
, lush green vegetation, thick stems but not a flower in sight! I wonder if the polar vortex impacted growth this year? I've had flowers bloom for the first time in 3 years (black eyed susans).

I am SOOO glad I found this forum! I purchased some of the seeds and I have 3' plants and not a single bloom! Some of them look like they have very tiny buds; this is a new flower for me though so I wasn't sure what to do with them, cut them down or leave them alone. I planted them as a temporary fix for an area that I was turning into a wildflower area. Now it just looks like I haven't mowed my lawn! I'll leave them for now and see what happens closer to October. I may have to till then under if they continue to grow without flowering. Thanks for all the comments, I thought I was going crazy!

Hi ..glad to see others with same plant and it growing so huge. Thought my yard was radioactive =)...the question I have is...are the orange cosmos wildflower that grew so big toxic to soil or herbs around it? I am harvesting and drying my pineapple sage but I see petals from cosmos on sage and it dried to leaves...need to know if will hurt anyone as I was using for gifting as dried herbs...are the orange cosmos edible or toxic?

I've grown the Bright Lights cosmos for about 6 years, first in Oregon and last year in my new home in Oakland CA. I maintain the bee-friendly garden at our public garden. No one knew about the orange cosmos I had come to love, I started some from Territorial Seed and they were abundant. I have always found there is no predicting the size - some small, some huge.

I tried to save seed this last year. They bloomed here well into our mild winter, at least January and maybe some even later. Awesome for our bees, some of whom forage all year here. I theorize that the bigger seeds will produce the bigger planes, we'll see. It's May, very few have germinated. I seem to recall from Oregon that they germinated late, they certainly started blooming mid summer but they lasted so long into the winter. Bees loved them, which I knew from observation, and our Monarchs are also crazy about them. We have a big Monarch program, so that was good news, food for them as the migrated and actually clustered this year in our garden, The Gardens at Lake Merritt.

I found the daylight-hours comments interesting, I will note when they germinate this year. Surely some must have self seeded in the garden. BTW, I deal with the huge thall ones by pruning them up 1-2 feet so the stems are bare, and planting other things beneath them. Otherwise the footprint is just too much real estate for our little space. They need a little staking if they get too top heavy.

My sister and I are having this same problem! The stem is as big around as my wrist, they are very tall but no flowers. What the heck and why?

Less water! they are more drought tolerant than most...

I can definitely say this is the one flower that benefits from NOT having rich healthy fertile soil! In fact it’s necessary that it DOESNT or u can end up w tall greens and no blooms...

once i move all my cosmos varieties to a bed w unamended sand (practically zero soil nutrition!) and forced myself to not water as much (deeper root growth that way) they all did so much better!

Including bright lights, sensation, apricot lemonade (shorter var.) and double whites I had leftover...I collect seed every fall amd only buy new for a new variety -

the flowers grown in sand/soil mix from same seed families dont get as many blooms for me!

I'm lucky to have a pure sand bed as i dont live far from what used to be shoreline...

its the one thing in the garden that is counter intuitive to everything we think of as needed for great flower production lol

The year i had big thick stems was the year we got a lot of rain, so i can pretty much get away w NEVER watering when it comes to cosmos — and let them live on rain water alone, they can go 4wks where i am, i will give one good deep water every two wks if it hasnt been raining thoroughly but thats about it! Never feed, rarely water, pinch back at 1' early in their season and basically leave them alone ...and they never fail for me in zone 4b

They are a late summer- early fall bloom time though, so not really a main event during primetime like July/August...i like that they give a big show at seasons end when most gardens are winding down, along w the dahlias and zinnias so maybe they benefit from cooler nights?