Cosmos are annual flowers with colorful daisy-like flowers that sit atop long slender stems. Blooming throughout the summer months, they attract birds, bees, and butterflies to your garden. Growing easily from seeds, cosmos even survive in poor soil conditions! Here’s how to grow cosmos.
Cosmos produce 3- to 5-inch daisy-like flowers in various colors, including pink, orange, red and yellow, white, and maroon. Their flowerheads may be bowl– or open cup–shaped. These beautiful plants can reach 6 feet tall.
Cosmos grow in both beds and containers—and they also make great cut flowers!
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Cosmos in pots at the end of the season
I have some lovely cosmos in a pot but now it's coming to the end of the season, I was wondering what I should do with it? I don't have a shed that I can store it in - will it still re-seed in the pot?
Reseeding Cosmos
Cosmos are aggressive reseeders, so it’s likely that you’ve got some seeds in the pot already. However, if the pot has had cosmos this year, you’re better off starting with fresh soil next year. This way, you won’t risk the continuation of pests and disease, and next year’s plants will have plenty of room and nutrients to help them grow their best.
To save seeds, watch for seedpods to develop on the plant and snip them off just before they a start to look dry. Keep these in a paper bag in a cool, dry place and spread the seeds once again in the spring.
Cosmos not seeding.
My cosmos bloom, but the seeds are too thin/tiny and weak. How to improve the seed grow for repotting? Also the stem are weak. How to strengthen the stem. Im leaving in Singapore is Singapore suitable for planting cosmos? There is one strong cosmos plant but not blooming. Should I cut it off?
Cosmos Problems
Lack of blooming could be caused by too much water, too little light, or too much fertilizer. We’re not personally familiar with the climate in Singapore, but if it’s too humid and wet, the cosmos may struggle. They prefer to be grown in well-draining soil in full sun.
Watering
How often and how much water should I water my cosmos plant and also how much soil should I use if I'm using 4" terra cotta pots and all-purpose soil? I'm doing an experiment for school and I need exact measurements.
Cosmos turning brown from the bottom up
My cosmos were during beautifully and the last few times I went out to dead head and water them I found several of the branches turning brown. I love these flowers and were so proud they are doing well up till now. Have watered them to much which I usually do daily cause it has been so hot and have fertilized them at least several times since planting them early this summer.
Need Help with Diseased Flowers
Hello, my daughters Cosmos have developed some sort of growth or disease - is this normal and can we get rid of it? They look like spikey legs growing on the stem. I have pictures but can’t upload them. My daughter grew these from seeds and they are beautiful - except this one. Please help. Thanks Bob
Spikey legs on stem of Cosmos
Since you could not provide a picture I'm not sure what you are looking at, but after the blossom dies off the blossom will be replaced by the seed heads which look like round "spikey balls" on the end of the branch. These spikey balls are made up of many seeds which can be easily harvested to be used for next year or they can be allowed to fall to the ground and reseed themselves.
Cosmos Seeds
"Where can I purchase Cosmos seeds. I'v checked local nurseries but they don't have them.
cosmos
Where can I buy cosmos seeds?
Cosmos Seeds
Try an online dealer, such as Burpee, Park Seed, or Territorial Seed Co.
Cosmos seeds
Dollar Tree when seeds were available
cosmos seeds
I bought mine here and am very happy! myseedneeds dot - com
PURCHASE OSMOS SEEDS
I got mine from Wilkinson's for about £1/2
Cosmos seeds
Go to American Meadows. I have liked everything I have purchased
Cosmos seeds
I would like to purchase cosmos seeds--variety of colors & some that do not grow really tall--Thank you!
Cosmos,Colors and Sizes
How to Plant and Grow
Looking for cosmos seeds
I am looking for cosmos seeds . Where can I get different coloured cosmos flower seeds.....Looking forward
Cosmos
Next to wild white Daisies with the yellow eye, Cosmos are a favorite. I too have a sandwich bag of Cosmo seeds. I am excited to get winter over so i can get the seeds growing. Thank you for the information. My question is," can i mix wild daisies in the same garden with the Cosmos?" Thanks again.
What plant to pair with Cosmos
This advice is too late for you, but hope it helps others. We’d sow our cosmos seeds in March or April. Harden off the seedlings before planting out in a sunny spot. Many flowers mix well with cosmos. We haven’t tried daisies but I’m sure they’d grow. It depends on the color of the cosmos. Against a white daisy, we probably would not pick a white cosmos; it would be better to have a deep magenta cosmos. However, it’s a personal preference!
cosmo seeds
i have a sandwich bag full cosmo seeds. plz sumone tell me how many seeds i need to plant per plant.
Cosmo Seed Spacing
Hi John,
Plant Cosmo seeds 2 feet apart to give them adequate space. This distance also gives them the benefit of leaning on each other when they are mature.
Cosmos end of season
Should the Cosmos be cut back? pulled out? left long/leggy? or what? Thanks. BTW - mine grew to at least 8' tall - Monarch, Painted Lady, and Skipper butterflies, and bees LOVE the flowers!!
Cosmos cut back?
Cosmos is an annual, so it will not continue to grow noticably (and will die) this growing season. However, it sometimes self seeds, so you may get more of the same…which sound spectacular! Kudos on the cosmos, Pat!
Grandma's old seeds
My grandmother is 90 and has dementia. I help take care of her and while going thru some old junk drawers I came across a package of cosmos seeds. I don't know how old they are, when she bought them, or if they are still any good or not but in the article it says they can be "self-sowing" so if this next spring I were to just take them out and scatter them in a bare place in the yard and water it occasionally, when I do the rose bushes say, do you think they might grow? Also she is wanting to plant something in her hanging baskets on the back porch is there anything we can plant now, in the mid-summer in zone 6 without going to the garden center and spending a lot on already half grown flowers?
Thanks for any help!
Cosmos Seeds
Cosmos seeds may last between three and four years in a cool, dry environment, so your grandmother’s seeds may still be viable. It’s worth giving them a try, in any case! Maybe buy a supplemental packet, too, if you can.
As for your hanging baskets: It’s a tad late to be starting most flowers from seed, unfortunately, however you do have a couple options. Pansies are probably your best bet if you want to start from seed. You may be able to find a few cheap impatiens, portulaca, and petunia transplants on sale at this time, too.
planting cosmo seeds in the fall
I live in southern NH and was wondering if I scattered Cosmo seeds in my wildflower field in September would they give me flowers next spring? Any special variety? TX
can I plant cosmos in the fall?
Hi, Kitty. Cosmos are best planted in the spring and need 7 weeks to grow, and will not survive the first fall frost.
Cosmo Question
Hi - I grow cosmos pretty successfully in rather lousy soil. It's gravely and full of clay right up against my house so I don't know far the roots can dig in but oddly they do well. I planted some in a terra-cotta pot that's about 12 inches high with potting soil and they have grown really tall - over 12 inches- no buds at all ! What do you think ?
no buds
Cosmos love lousy soil, so you’ve mastered that. It may be that the potting soil in you pot is too rich! Soil that is too nutrient rich produces plants that are weak-stemmed and have few to no flowers. Be sure that it drains really well!
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