Cosmos certainly are a great annual to enjoy through the growing season. With that being said, your issue with thick stems, lots of leaves, and few flowers is an interesting occurrence. One reason for it could be too much nitrogen. Cosmos are sensitive to nitrogen and it can cause exactly what happened to some of yours. If you have been fertilizing those cosmos (or maybe it came from fertilizer spread on the lawn) you should cut back on fertilizing—or stop all together. If you need to fertilize, do so with a mix that is low in nitrogen. It is completely up to you if you want to pull them out because of space issues, but you could also wait to see if flowers arrive later in the season.
Hi Suellen,
Cosmos certainly are a great annual to enjoy through the growing season. With that being said, your issue with thick stems, lots of leaves, and few flowers is an interesting occurrence. One reason for it could be too much nitrogen. Cosmos are sensitive to nitrogen and it can cause exactly what happened to some of yours. If you have been fertilizing those cosmos (or maybe it came from fertilizer spread on the lawn) you should cut back on fertilizing—or stop all together. If you need to fertilize, do so with a mix that is low in nitrogen. It is completely up to you if you want to pull them out because of space issues, but you could also wait to see if flowers arrive later in the season.