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 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
I bought mine here and am very happy! myseedneeds dot - com
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!
Good soil is no good ?!?
So the seeds I planted in the terra-cotta pot look super healthy,lush, green and strong not "weak" at all. I used a generic potting soil from Wal Mart. I'm thinking they have more room to spead roots and maybe when they can't go further they'll bloom ? If I want to try in a pot next year what "soil" should I use ?
what soil?
As noted above in response and in guidance, cosmos are not demanding. Your generic potting soil is probably fine; “lousy” was your word re your in-ground cosmos and we meant only that potting soil does not need to be rich/composted/fertilized. Another thought is that you use the in-ground soil in the pot. If indeed the pot is appropriate. You may have identified the problem as a too-small pot; the cosmos may need more leg room, so to speak. Does this help?
Cosmos
Mine have done pretty much the same thing. I bought them in a packet and planted them in a small bucket with potting soil, and they are almost 8 inches tall, but no buds also. I water them about every other day and they get a full day of sunlight... are they going to bud and bloom eventually?
tough love
This may sound odd, but cosmos like very tough, poor conditions. Low soil fertility. Very little water. If you overcare for them (too much water, too much fertility and too much shade), cosmos becomes tall and spindly and blooms sparsely. They like it hot and dry. Think Texas. When not exposed to “tough-love” growing conditions, this otherwise beautiful flowering plant becomes tall, spindly and sparsely floriferious.
Flowers in Arizona
I want to grow potted plants for around my pool area. I'm looking for the following information:
1. What do you suggest I plant? I would like a lot of color.
2, What type of soil would I use?
Thank you for your help!! :)
Pots around pool area
We imagine you’ll want flower pots that are heat-tolerant and can take full sun. Consider gomphrena, lantana or scaevol, for starters. For annuals in containers, use a medium weight potting mix. But first fill the bottom 1 to 2 inches of the pot with coarse gravel and then a 1⁄2-inch layer of fine gravel or sand.
Flowers dying quickly
I have a cosmos plant that I grew from seeds that is doing very well. The plant is about 2 ft tall and it has recently started to produce flowers. However, the flowers are turning brown and drying up within a few days of blooming. Is this normal?
Flowers Drying Up
If you are experiencing particularly wet or dry conditions, this could be the cause of your short-lived flowers. Cosmos are generally drought-tolerant, but if it’s been very dry and hot, then your flowers could be getting sunburnt.
Cosmos growing so slowly!
I live in the SF bay area (zone 9b) and planted a few cosmos seeds (Sensation blend) at the end of April and then again in early May this year. It's the end of June now - about two months later - and each plant is just 4 - 5 inches tall. The plants are in almost full sun - they get several hours of sun per day. They look healthy and green but aren't growing much. I'm wondering what could be the problem...I was hoping to have at least some flowers by now. Anyone have any ideas on what might be going on?
cosmos
Cosmos likes at least 6 hours of sunlight each day. It may take about 85 days for the Sensation variety to reach maturity, so it could be that it just needs more time. Be sure that the soil is well-drained. Also be sure that the plants are thinned to the proper spacing and that there are no weeds nearby that are competing for nutrients, space, and light.
Speedy sproutlings
I was stunned that my pictoee cosmos only took 4 days to sprout from seed as the package said 7 days minimum. That's fast! I started them indoors at the same time as about four dozen other flower and vegetable species, and they're the only ones to break the surface so far. I used soil-less substrate in paper pots, kept just moist enough, and they are under full spectrum artificial lights for several hours a day.
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