When to Plant Coreopsis in Grand County, UT
Top priorities for Grand County, Utah gardeners in June
A quick June briefing for Grand County, Utah gardeners — what's urgent, what's next, and what can wait.
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Begin indoor sowing: coreopsis
Your window is short. These crops want several weeks of indoor growth before they go outside.
Looking ahead to July
- First harvests: coreopsis
Coreopsis (Tickseed) is a cheerful, long-blooming native perennial that produces a continuous flush of bright yellow, gold, or bi-colored daisy-like flowers from early summer well into fall. One of the most reliable cut-and-come-again bloomers in the perennial garden, it thrives in hot, dry, sunny conditions and poor soil where many competitors struggle. An invaluable nectar source for native bees and butterflies, and a butterfly host plant for several species.
Grand County, Utah is in USDA Zone 6b. The average last spring frost is April 19 and the first fall frost is October 13, giving you a growing season of approximately 177 days.
At an elevation of 5,415 feet, Grand County receives approximately 23.1 inches of rainfall annually with predominantly loam soil. Summer highs average 91°F, providing good warmth for Coreopsis during the growing season.
Grand County Soil Profile
Soil Type
Loam
Soil pH
6.4-7.9
Drainage
Well Drained
Coreopsis Planting Risk Windows
Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.
Soil Compatibility in Grand County
How your county's soil matches Coreopsis's growing requirements.
Soil pH
Your soil pH (6.4–7.9) overlaps with Coreopsis's range (5.5–7.5), though not a perfect match.
Soil Texture
The loam soil in Grand County is excellent for Coreopsis — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Coreopsis.
Organic Matter
Organic matter is moderate (2.1%). Annual compost additions will help Coreopsis.
How to Plant Coreopsis
Succession Planting Coreopsis
Sow every 6.9 weeks. Last sowing by Jul 25 to harvest before frost.
Coreopsis Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Coreopsis
Coreopsis needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.
| Month | Coreopsis Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.3" | 0" | ❄️ Dormant |
| Mar | — | 2.2" | 0" | ❄️ Dormant |
| Apr | 2.2" | 2.2" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 2.9" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 1.5" | 0.7" | 💧 Light watering |
| Jul | 2.2" | 2.4" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 2.1" | 0.1" | 💧 Light watering |
| Sep | 2.2" | 1.8" | 0.4" | 💧 Light watering |
| Oct | 2.2" | 2.1" | 0.1" | 💧 Light watering |
| Nov | — | 1.6" | 0" | ❄️ Dormant |
| Dec | — | 1.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Grand County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Coreopsis Heat Requirements (GDD)
What are Growing Degree Days (GDD)?
Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.
Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.
Coreopsis Planting Timeline — Grand County, UT
Coreopsis Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 15 | Feb 15 – Mar 1 |
| Transplant Outdoors | April 26 | Apr 26 – May 10 |
| Direct Sow | April 19 | Apr 19 – May 10 |
| Bloom | July 5 | Jul 5 – Nov 1 |
Plant 0.1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors |
| April | Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | Bloom |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Only during dry spells
📅 Days to Maturity
60–80 days
🧪 Soil pH
Needs 5.5–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 6b
📆 Growing Season
177 days in Grand County
Growing Tips for Coreopsis in Grand County
Direct sow Coreopsis outdoors after April 19 in Grand County when soil has warmed and frost danger has passed.
Common pests for Coreopsis in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.
Grand County receives only 23" of rain annually. Coreopsis needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Start seeds indoors 8–10 weeks before last frost or direct sow after last frost. Seeds germinate easily without stratification. Thrives in poor to average, well-drained soil — rich soil promotes foliage over flowers. Drought tolerant once established; overwatering is the most common mistake. Deadhead spent blooms to maintain continuous flowering through the season. Shear plants by one-third in midsummer for a fresh flush of late-season blooms. Year 2+ plants bloom most heavily. Divide every 2–3 years in early spring to rejuvenate crowded clumps.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Coreopsis in Other Locations
Frequently Asked Questions
When should I plant Coreopsis in Grand County, UT?
Grand County is in Zone 6b with an average last frost of April 19. Plan your Coreopsis planting based on this frost date — see the calendar above for exact timing.
What planting zone is Grand County, UT?
Grand County, Utah is in USDA Hardiness Zone 6b. The average last spring frost is April 19 and first fall frost is October 13.
Your Grand County Garden Planner — Free
A 22-page printable planner built for Grand County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.