Threadleaf coreopsis or tickseed (Coreopsis verticillata) is a fine-leaved flowering perennial that has tons of great varieties to choose from. It is a terrific plant for perennial gardens and massing. Most varieties grow 1-2 feet high and spread 1-2 feet or more. Coreopsis has a long bloom period when deadheaded and, in some ways, blooms more like an annual than a perennial. Coreopsis does best in full sun but can handle part sun. In full sun, it blooms more profusely and grows more densely. Likes moist, well-drained soils but is drought tolerant once established and does poorly in overly moist soils.
Tickseed spreads via rhizomes and self seeds so it can get a bit pushy in a perennial garden. Plan on keeping it in check as needed. Even with the extra work it offers such a great bloom period and fine textured foliage that its hard to pass up if you have part to full sun available.
Notable varieties: ‘Moonbeam’ is a lovely light yellow variety that is especially beautiful. ‘Zagreb’ which is a shorter growing variety and there is a great pink variety Coreopsis rosea (Pink Tickseed).
|Threadleaf coreopsis or tickseed
|Late spring/Summer blooming perennial with fine featherry foliage that is a fast spreader and has a season long bloom period.
|green fine feathery texture.
|Single layer of smooth petals surrounding a small yellow centers.
|June to September
|Loamy. Moist well-drained soils are best.
|Full sun to part sun
|Nice dense spreading habit. Massing and grouping are great options. Fine texture foliage and a long bloom period. Great for massing.
|Watering weeklyif needed is typically best. Can handle some drought conditions.
|Not required but always helps especially if you need to add organic matter to the soil.
|Not needed if you have healthy humus-rich soil with plenty of organic matter.
|Does a great job at stifling weeds due to its dense mound like foliage that keeps most weeds from getting through.
|Deadhead individual spent flowers to prevent it from going to seed and to rebloom.
|Yes, in early spring as they emerge or early fall
|Early spring when they start to appear or early fall is best but anytime works with sufficient watering.
|If planted in the right conditions it has few pests.
|Cut back any stems that remain 2-3 inches above the ground after the first hard frost or two (when the ground freezes). You can also use straw or pile some leaves over the plants.