When to plant Coreopsis in Solano County, CA
Coreopsis planted in Solano County between January 19 and February 9 matures in 60–80 days — well before the December 3 first frost.
When to Plant Coreopsis in Solano County, CA
June in Solano County, California — your action list
Your garden in Solano County, California is working on a schedule, even when you're not. Here's where you should be this June.
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Pick coreopsis
This is the payoff month. Bring a basket, bring a friend, and get into the beds.
Before July arrives, get these ready
- 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.
Solano County, California is in USDA Zone 9b. The average last spring frost is February 9 and the first fall frost is December 3, giving you a growing season of approximately 297 days.
At an elevation of 376 feet, Solano County receives approximately 40.4 inches of rainfall annually with predominantly loam soil. Summer highs average 95°F, so Coreopsis may need afternoon shade and extra watering during peak heat.
Solano County Soil Profile
Soil Type
Loam
Soil pH
6.8-7.3
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 Solano County
How your county's soil matches Coreopsis's growing requirements.
Soil pH
Your soil pH (6.8–7.3) is within Coreopsis's preferred range (5.5–7.5).
Soil Texture
The loam soil in Solano 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 (2.6%). Annual compost additions will help Coreopsis.
How to Plant Coreopsis
Succession Planting Coreopsis
Sow every 6.9 weeks. Last sowing by Sep 14 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 | — | 8.9" | 0" | ❄️ Dormant |
| Feb | 2.2" | 8.4" | 0" | ✅ Rainfall sufficient |
| Mar | 2.2" | 6.6" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 2.7" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 1" | 1.2" | 🚿 Regular watering |
| Jun | 2.2" | 0.2" | 2" | 🚿 Regular watering |
| Jul | 2.2" | 0" | 2.2" | 🚿 Regular watering |
| Aug | 2.2" | 0" | 2.2" | 🚿 Regular watering |
| Sep | 2.2" | 0.4" | 1.8" | 🚿 Regular watering |
| Oct | 2.2" | 1.9" | 0.3" | 💧 Light watering |
| Nov | 2.2" | 3.3" | 0" | ✅ Rainfall sufficient |
| Dec | 2.2" | 7.1" | 0" | ✅ Rainfall sufficient |
Water needs are for active growing months only (Feb–Dec in Solano 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 — Solano County, CA
Coreopsis Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | December 15 | Dec 15 – Dec 29 |
| Transplant Outdoors | January 26 | Jan 26 – Feb 9 |
| Direct Sow | January 19 | Jan 19 – Feb 9 |
| Bloom | March 23 | Mar 23 – Aug 24 |
Plant 0.1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Transplant Outdoors Direct Sow |
| February | Transplant Outdoors Direct Sow |
| March | Bloom |
| April | Bloom |
| May | Bloom |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | — |
| October | — |
| November | — |
| December | Start Indoors |
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: ideal
🗺️ USDA Zone
Zone 9b
📆 Growing Season
297 days in Solano County
Growing Tips for Coreopsis in Solano County
Direct sow Coreopsis outdoors after February 09 in Solano 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.
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 Solano County, CA?
Solano County is in Zone 9b with an average last frost of February 9. Plan your Coreopsis planting based on this frost date — see the calendar above for exact timing.
What planting zone is Solano County, CA?
Solano County, California is in USDA Hardiness Zone 9b. The average last spring frost is February 9 and first fall frost is December 3.
When should I plant Coreopsis in Solano County, CA?
In Solano County, CA, plant Coreopsis after the last frost (around February 9) and before the first frost (around December 3). Best results when soil holds above 50°F.
What growing zone is Solano County, CA for Coreopsis?
Solano County sits in USDA Zone 9b. Coreopsis grows reliably in zones 3a through 9b, so it's a good fit here.
Can Coreopsis grow in Solano County's climate?
Yes — Coreopsis grows well in Solano County's temperate climate. Solano County averages a 298-day frost-free season, with last frost around February 9 and first frost around December 3.
Your Solano County Garden Planner — Free
A 22-page printable planner built for Solano County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.