When to plant Coreopsis in Bonner County, ID
Bonner County gardeners should plant Coreopsis between May 5 and May 26 in spring. With Bonner County's Zone 6b climate (last frost May 5), Coreopsis needs 60–80 days to mature — plant by July 15 for a full harvest.
When to Plant Coreopsis in Bonner County, ID
Your June gardening checklist
Welcome to June in Zone 6b. These are the moves that will have the biggest impact on your growing season.
July prep starts now
- Starting indoors: coreopsis
- 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.
Bonner County, Idaho is in USDA Zone 6b. The average last spring frost is May 5 and the first fall frost is October 3, giving you a growing season of approximately 151 days.
At an elevation of 7,480 feet, Bonner County receives approximately 12.9 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Coreopsis during the growing season. With low rainfall, drip irrigation is essential for growing Coreopsis successfully. Mulch heavily to conserve soil moisture.
Bonner County Soil Profile
Soil Type
Loam
Soil pH
6.4-8.2
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 Bonner County
How your county's soil matches Coreopsis's growing requirements.
Soil pH
Your soil pH (6.4–8.2) overlaps with Coreopsis's range (5.5–7.5), though not a perfect match.
Soil Texture
The loam soil in Bonner County is excellent for Coreopsis — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.4%). Annual compost additions will help Coreopsis.
How to Plant Coreopsis
Succession Planting Coreopsis
Sow every 6.9 weeks. Last sowing by Jul 15 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 | — | 0.9" | 0" | ❄️ Dormant |
| Feb | — | 0.7" | 0" | ❄️ Dormant |
| Mar | — | 1.1" | 0" | ❄️ Dormant |
| Apr | — | 1.5" | 0" | ❄️ Dormant |
| May | 2.2" | 1.5" | 0.7" | 💧 Light watering |
| Jun | 2.2" | 0.9" | 1.3" | 🚿 Regular watering |
| Jul | 2.2" | 1.1" | 1.1" | 🚿 Regular watering |
| Aug | 2.2" | 1.2" | 1" | 💧 Light watering |
| Sep | 2.2" | 1.1" | 1.1" | 🚿 Regular watering |
| Oct | 2.2" | 1.1" | 1.1" | 🚿 Regular watering |
| Nov | — | 0.9" | 0" | ❄️ Dormant |
| Dec | — | 0.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Bonner 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 — Bonner County, ID
Coreopsis Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 3 | Mar 3 – Mar 17 |
| Transplant Outdoors | May 12 | May 12 – May 26 |
| Direct Sow | May 5 | May 5 – May 26 |
| Bloom | July 21 | Jul 21 – Nov 17 |
Plant 0.1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | — |
| 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
151 days in Bonner County
Growing Tips for Coreopsis in Bonner County
Direct sow Coreopsis outdoors after May 05 in Bonner 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.
Bonner County receives only 13" 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 Bonner County, ID?
Bonner County is in Zone 6b with an average last frost of May 5. Plan your Coreopsis planting based on this frost date — see the calendar above for exact timing.
What planting zone is Bonner County, ID?
Bonner County, Idaho is in USDA Hardiness Zone 6b. The average last spring frost is May 5 and first fall frost is October 3.
When should I plant Coreopsis in Bonner County, ID?
In Bonner County, ID, plant Coreopsis after the last frost (around May 5) and before the first frost (around October 3). Best results when soil holds above 50°F.
What growing zone is Bonner County, ID for Coreopsis?
Bonner County sits in USDA Zone 6b. Coreopsis grows reliably in zones 3a through 9b, so it's a good fit here.
Can Coreopsis grow in Bonner County's climate?
Yes — Coreopsis grows well in Bonner County's temperate climate. Bonner County averages a 151-day frost-free season, with last frost around May 5 and first frost around October 3.
Your Bonner County Garden Planner — Free
A 22-page printable planner built for Bonner 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.