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New Member
I am a beginner gardener and made the mistake of planting two 25 cent packets of cosmos in my garden and promptly forgot about them. I neglected to stake them, so they grew horizontally, about 4-5 feet in length. When I cut them back I had to use an AXE, some stems 8" in diameter. Please tell me these things are not going to come back next year? Thanks!


Super Moderator
Staff member
Welcome to our forum Kelly!
Depending on which zone you live in they may, or may not reseed!
If they do they can be easily stomped, or turned under!
If you live in a colder zone like my zone 5 they will not survive our winter temps!

Kya D

Active Member
I love cosmos
But they will come back yearly from reseeding.
Ron is right about stomping them, also if they start to bud just cut the buds off.
BTW Welcome to the forum glad to see you here.


A few year ago cosmos was ‘n big problem in South Africa. It was classified as a weed. In the towns it’s not a problem because you can cut out the flowers before they make seeds. But where the problem started was in the big open spaces. I remember when I was younger when we went up to the farm you see all the cosmos plants flowering in spring time next to the roads in the fields. To day you don’t see it any more. We have to spray with a chemical if we find them on the farm.


Super Moderator
Staff member
Welcome Kelly! If there are still flowers or seed heads on the plants. pull them off before they open to prevent reseeding.


We have many invasive species of "wildflowers" that are problems. You would think something so beautiful would not become a weed. But it happens. is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to