Coreopsis height and bloom - Ask Extension
I bought a small corriopsis start at the Nehalem master gardener sale in March It has grown to the height of 6' before the blooms ever started. Now it...
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Coreopsis height and bloom #805963
Asked August 12, 2022, 1:52 PM EDT
I bought a small corriopsis start at the Nehalem master gardener sale in March It has grown to the height of 6' before the blooms ever started. Now it's blooming quite well but not sure why it got so tall? Should I cut it back down late fall?
Tillamook County Oregon
Expert Response
Dear Dennis,
Thank you for contacting Ask Extension about your coreopsis
or Tickseed. There are many types of coreopsis, including both annuals and perennials. Yours appears to be Coreopsis tinctoria which is an annual. Would that be correct?
Normally, C. tinctoria grows up to 4 feet, but it may get bigger especially if you fertilized it. These plants should not be fertilized for this reason. When they get too tall, it is usually necessary to stake them.
Tickseed can be prolific a self-seeder to the point that it can get weedy. To avoid this, deadhead the flowers as they mature. Deadheading may also encourage a rebloom.
If you want the seed, leave a few of the flowers on the plant and harvest them when they are mature. You can cut the plant back if it becomes unmanageable or looks messy; but leave a foot or so standing through the winter to provide habitat for insects and help protect the soil.
I hope this information is helpful. Please write again if you have other questions.
Thank you for contacting Ask Extension about your coreopsis
or Tickseed. There are many types of coreopsis, including both annuals and perennials. Yours appears to be Coreopsis tinctoria which is an annual. Would that be correct?
Normally, C. tinctoria grows up to 4 feet, but it may get bigger especially if you fertilized it. These plants should not be fertilized for this reason. When they get too tall, it is usually necessary to stake them.
Tickseed can be prolific a self-seeder to the point that it can get weedy. To avoid this, deadhead the flowers as they mature. Deadheading may also encourage a rebloom.
If you want the seed, leave a few of the flowers on the plant and harvest them when they are mature. You can cut the plant back if it becomes unmanageable or looks messy; but leave a foot or so standing through the winter to provide habitat for insects and help protect the soil.
I hope this information is helpful. Please write again if you have other questions.
Thanks so much for the reply. It was marked as a Coreopsis Mardi Gras. I did fertilize with Miracle Grow. We live a mile or so from the coast and the yard was mostly fir trees which are now removed and I am the first to plant anything in many years I believe, so many things are experimental and pioneering here. I will work on it.
You are very welcome, Dennis. 'Mardi Gras' is shown as an annual. You may want to save some seeds to make sure you still have the plant in the future.
https://www.gardenia.net/plant/coreopsis-tinctoria-mardi-gras
https://www.gardenia.net/plant/coreopsis-tinctoria-mardi-gras
