Coreopsis (Tickseed) in Zone 4a & 4b
Coreopsis grandiflora
Yes, coreopsis (tickseed) grows in zones 4a and 4b. Start seeds indoors Mar 27–Apr 3 and plant out May 22–May 29.
When to plant coreopsis (tickseed) in zone 4b
Zones 4a and 4b share the same average frost dates, so this page covers both.
Method: Either: Start indoors for an earlier harvest, or direct-sow outside for less fuss. Either works.
| Start indoors | Mar 27–Apr 3 |
|---|---|
| Direct sow / transplant outside | May 22–May 29 |
| Estimated bloom | Aug 10–Aug 17 (~80 days after planting) |
Spacing: 1 per square foot (square-foot-gardening spacing). Mature height: 1-2 ft.
Plant alongside it in zone 4b
These go outside within two weeks of coreopsis (tickseed) in zone 4b, so one planting day can cover them.
- NasturtiumMay 22–May 29
- MarigoldMay 22–May 29
- Ageratum (Flossflower)May 22–May 29
- Annual Geranium (Pelargonium)May 22–May 29
- Butterfly Weed (Asclepias)May 22–May 29
- Campanula (Bellflower)May 22–May 29
Coreopsis (tickseed) is a native perennial grown for cheerful yellow blooms and for how reliably it pulls in pollinators. It's one of the better-documented native plants for supporting a wide range of bee species specifically. Buy it as straight species seed rather than a named cultivar: garden-center coreopsis is often sold under trademarked names bred more for compact habit or bloom color than for vigor, and at least one of the most common, 'Moonbeam', has turned out to carry a flower disease that's spread through nursery stock over the past decade.
How coreopsis (tickseed) fits zone 4's season
Zone 4b's frost-free window runs about 128 days, from May 15 to September 20. Coreopsis (tickseed) needs about 80 days from sowing to first bloom.
Coreopsis (Tickseed) planting windows in every zone
Zone 4b is highlighted. Useful for comparing against a neighbouring zone, or for a garden somewhere else.
| Zone | Start indoors | Sow or plant out | Bloom |
|---|---|---|---|
| 4a & 4b (your zone) | Mar 27–Apr 3 | May 22–May 29 | Aug 10–Aug 17 |
| 5a & 5b | Mar 22–Mar 29 | May 17–May 24 | Aug 5–Aug 12 |
| 6a & 6b | Mar 7–Mar 14 | May 2–May 9 | Jul 21–Jul 28 |
| 7a & 7b | Feb 20–Feb 27 | Apr 17–Apr 24 | Jul 6–Jul 13 |
| 8a & 8b | Feb 4–Feb 11 | Apr 1–Apr 8 | Jun 20–Jun 27 |
| 9a & 9b | Dec 28–Jan 4 | Feb 22–Mar 1 | May 13–May 20 |
| 10a & 10bSpring window | Jan–Mar | Mar–May | ~80 days after transplanting |
| Fall window | Aug–Sep | Oct–Nov | ~80 days after transplanting |
Bloom dates are about 80 days after the sow or plant-out date, not after starting seeds indoors.
Good companions
- Bell Pepper: Draws in pollinators and beneficial insects like lady beetles near heavy-feeding vegetables.
Where to buy coreopsis seeds
Botanical Interests · True Leaf Market · Burpee (each supplier's coreopsis seeds)
See why we recommend these suppliers →
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See it growing
Search YouTube for "growing coreopsis (tickseed)" videos → (a live search, not a hand-picked video; results vary and aren't vetted by us)
← Back to the full zone 4b calendar · Plan your beds in the Garden Designer →
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Growing Coreopsis (Tickseed) in USDA zone 4b: when to start seeds indoors, when to direct-sow, and when to expect a bloom.
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