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Cosmos plants 2-3 times larger than others.

Posted by albert_135 Sunset 2 or 3 (My Page) on
Sun, Aug 10, 08 at 13:51

I tossed some old cheap packages of purple cosmos seed, raked and watered and have purple cosmos blooming 2-3 feet tall.

Among these plants are two plants that look like the others except they are 5-6 feet tall, one inch diameter stems and no flowers yet.

Is this much variation normal?


Follow-Up Postings:

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RE: Cosmos plants 2-3 times larger than others.

Sorry. I was slapped with the surprising admonition that cosmos is not an annual and that I had posted on the wrong forum and that I should bugger off.


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RE: Cosmos plants 2-3 times larger than others.

  • Posted by remy 6WNY (My Page) on
    Fri, Aug 15, 08 at 13:46

Albert,
Huh? Cosmos is an annual : ) Maybe in really hot climates it is not, or maybe certain types like Chocolate Cosmos is a tender perennial, but for most people it is an annual.
I'm not sure how much variation there is. I do know they like it lean and the bigger ones may be in spots with more water and/or fetilizer. Hopefully the big ones bloom soon. I do know they will bloom through autumn and even light frosts.
Remy


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RE: Cosmos plants 2-3 times larger than others.

My two big cosmos are now 6 and 7 feet tall and still no blooms. They are growing with the others so fertilizer and water are the same.

So, now I am wondering if the big ones should ever bloom (I might still have eight weeks before frost or it might frost next month.) should I make some effort to self pollinate them and collect the seed?

Or is seven foot and a late bloomer still within "normal"?


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RE: Cosmos plants 2-3 times larger than others.

Persons on Winter Sowing forum are discussing tall cosmos, some that don't bloom before frost. I'm still curious. When do these 6-8 foot cosmos bloom when weather allows?


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RE: Cosmos plants 2-3 times larger than others.

Most Cosmos are annuals, and most Cosmos are not seven feet tall, but some do get that tall and will bloom if planted in enough sun and the season where you live is long enough. I am sorry you were chastised for your post, some gardeners, like most people are "up tight" sometimes. Al


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RE: Cosmos plants 2-3 times larger than others.

in order for Cosmos to bloom, it must be neglected. Poor soil is ideal. It was my first time last year to grow Cosmos and I neglected it and it had tons of flowers. Someone mentioned on a forum that he fertilized his cosmos and only got very few flowers.

This year, I did the same, I neglected, it had tons of flowers. It's still flowering as of today. :)


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RE: Cosmos plants 2-3 times larger than others.

I live in Arizona and just I few months ago in November my cosmo plant had reached about 8 feet tall and just barely had time to flower before we got hit with a really hard frost that ended up killing half the plant. But never the less I had also had an experience similar to yours and wondered if it was ever going to flower :p I had planted my seedlings in the middle of spring witch for Arizona was around mid march so I would Have expected it to flower much earlier in the season, but I would now say it is quite typical and possible to happen again if you plant during the same time of year some cosmos just don't flower till the photoperiod shortens dramatically.


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RE: Cosmos plants 2-3 times larger than others.

excessive green growth CAN BE an indication of excessive fertilizer .... especially the nitro side ... as in lawn fert applied to the flower bed ...

this is echoed by the comment above that said:

in order for Cosmos to bloom, it must be neglected. Poor soil is ideal.

fertilizing .. simply for the fact of 'feeding' your babies can become problematic ...

i learned this lesson one year.. when i put FRESH manure all over the beds .... boy did i grow a jungle that year ... at the expense of proper flowering ...

but look out.. the following years i had super soil ....

ken


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RE: Cosmos plants 2-3 times larger than others.

Hi there,
I think I remember from some German book on annuals that Cosmos used to be/are a kind of "short day plant" meaning they require rather short days to induce flowers. So that means after the summer.
The modern or present cultivars are bred for earlier flowers and often for shorter stems (better for small gardens, less flopping over...).
So could be that the tall ones are of the more old fashioned kind, reverted to the more native type by mutation or whatever.
I watched some Cosmos grow and flower happily in a friends allotment last summer, on heavy clay soil, lots of rain, so no starving for those.
Bye, Lin


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RE: Cosmos plants 2-3 times larger than others.

There has been a thread about this same issue on the wintersowing forum since last summer or even before. Lots of people experiencing very tall cosmos with no blooms for extended seasons. I've had the same issue with all of my cosmos--probably because I'm growing seeds that I collected late in the season from some of these tall plants.

Martha


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RE: Cosmos plants 2-3 times larger than others.

Last year, 2010, some of my tall cosmos were just beginning to bloom when we got our first serious frost. I cut off the tops of some and put them in a vase of water. I got blooms with seed and vigorous roots. I could not keep the rooted cuttings alive.

Some of the seed that matured inside were viable and I now have cosmos blooming in pots in February inside. They are not particularly impressive but it is happening nonetheless.


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RE: Cosmos plants 2-3 times larger than others.

Cosmos with little water and poor soil will grow up to 8 feet tall and bloom late unless they are the varieties that have been bred to be shorter. I grew them last year with NO water and NO fertilizer and the orange and yellow natural variety grew almost 9 feet with no blooms until August(with some very hoary thick stalked bushy ones at 10 feet that only bloomed almost a week before frost in October. The same seeds with water and fertilizer grew only three feet and bloomed in July.


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RE: Cosmos plants 2-3 times larger than others.

I'm having the opposite problem.My cosmos is only 5 or 6 inches tall and now has started blooming. We had a cold wet spring and summer heat then hit us hard. I'm hoping their strange behavior is the result of the weather and not the gardener -- although I can't think of anything I've done that could stunt them so.


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RE: Cosmos plants 2-3 times larger than others.

I usually sew a few packs of cosmos every year. Last year I got several 5 and 6 foot plants. They flowered the same as their smaller brothers and sisters. Sur
e was cool to have those cosmo "trees" in the garden. :)


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RE: Cosmos plants 2-3 times larger than others.

Maybe my ground isn't radioactive after all! I planted Bright Lights and a purple mix in the spring and they grew to three or four feet. As they finished, new plants quickly grew under them from the seeds they set. The tallest is now over seven feet and they are covered with flowers in various shades of orange. And they're still coming up everywhere. I just cut the ones in the picture today. I'm hoping they'll continue to naturalize because I love cosmos! I'm in Central Florida.


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RE: Cosmos plants 2-3 times larger than others.

One of my tall cosmos near a sprinkler fell over a couple of months ago and has rooted in several places and has put up several shoots near the nodes that rooted. Now there are many fine flowers from these shoots. These flowers are larger than the other on taller stems nearby.


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RE: Cosmos plants 2-3 times larger than others.

I have very rich soil and my cosmos do fine. They are in full sun. The grow quite tall and begin blooming in August until a heavy frost kills them. (I do pinch them to encourage lateral in July).


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RE: Cosmos plants 2-3 times larger than others.

It's always good to know we're not alone when something in the garden acts weird! I planted an orange-flowering cosmos years ago and let it reseed on its own. Sometimes after the earliest plants went to seed & looked ratty I'd pull them up and let a new crop grow for fall.
But like passion4tropicals, this year the early plants were normal height & were blooming & setting seed by mid-May. Now in July, the second crop of seedlings have become enormous without a hint of a bud. I don't think much has changed in that bed, but now I'm wondering whether the original seeds were a cross, and these titanic Cosmos are actually one of the parents.

Annie at the Transplantable Rose


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RE: Cosmos plants 2-3 times larger than others.

Just wait. Those really tall ones will have 100 flowers. Every year someone posts here about those tall ones. They just take longer to flower. But what a show.


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RE: Cosmos plants 2-3 times larger than others.

Thanks for the answer, Susanzone5. There were too many large seedlings for the space & they were shading out everything else, so I pulled some, left some, and will now try to be patient!


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RE: Cosmos plants 2-3 times larger than others.

I sowed seeds for six cosmos plants indoors on 4/28/13. They all varied in height and bloom time. My tallest started blooming on 9/30 (which is just bizarre). At 6.5 feet, it is absolutely statuesque.


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RE: Cosmos plants 2-3 times larger than others.

How funny, SingSk8! We're many miles apart but the first buds on my weird cosmos formed the last week in September and are in full bloom now. One is over 7-ft tall and others might have been taller if staked - instead they've been bent over by wind & rain.
In the meantime, other self seeded plants popped up, stayed under 20-inches in height, and bloomed in early September.
The giants are fun & interesting, but the 2-ft plants fit the bed much better.

Annie


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