When to plant Coreopsis in Isleton, CA
Isleton sits in USDA Zone 9b. Plant Coreopsis between January 22 (after last frost on February 12) and February 12.
When to Plant Coreopsis in Isleton, CA
This month in Sacramento County, California
If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.
-
Collect coreopsis at their peak
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
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.
Isleton, California is in USDA Zone 9b. The average last spring frost is February 12 and the first fall frost is December 1, giving you a growing season of approximately 292 days.
At an elevation of 263 feet, Sacramento County receives approximately 33.2 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Coreopsis during the growing season.
Isleton Soil Profile
Soil Type
Loam
Soil pH
6.4-7.1
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 Isleton
How your county's soil matches Coreopsis's growing requirements.
Soil pH
Your soil pH (6.4–7.1) is within Coreopsis's preferred range (5.5–7.5).
Soil Texture
The loam soil in Sacramento 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 Sep 12 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 | — | 6.1" | 0" | ❄️ Dormant |
| Feb | 2.2" | 7.5" | 0" | ✅ Rainfall sufficient |
| Mar | 2.2" | 5.7" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 2.5" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 0.8" | 1.4" | 🚿 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" | 0.3" | 1.9" | 🚿 Regular watering |
| Oct | 2.2" | 1.4" | 0.8" | 💧 Light watering |
| Nov | 2.2" | 2.7" | 0" | ✅ Rainfall sufficient |
| Dec | 2.2" | 5.9" | 0" | ✅ Rainfall sufficient |
Water needs are for active growing months only (Feb–Dec in Sacramento 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 — Isleton, CA
Coreopsis Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | December 18 | Dec 18 – Jan 1 |
| Transplant Outdoors | January 29 | Jan 29 – Feb 12 |
| Direct Sow | January 22 | Jan 22 – Feb 12 |
| Bloom | March 26 | Mar 26 – Aug 27 |
Plant 0.1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors 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
292 days in Sacramento County
Growing Tips for Coreopsis in Isleton
Direct sow Coreopsis outdoors after February 12 in Sacramento 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
When should I plant Coreopsis in Isleton, CA?
In Isleton, CA, plant Coreopsis after the last frost (around February 12) and before the first frost (around December 1). Best results when soil holds above 50°F.
What growing zone is Isleton, CA for Coreopsis?
Isleton sits in USDA Zone 9b. Coreopsis grows reliably in zones 3a through 9b, so it's a good fit here.
Can Coreopsis grow in Isleton's climate?
Yes — Coreopsis grows well in Isleton's temperate climate. Isleton averages a 293-day frost-free season, with last frost around February 12 and first frost around December 1.
Your Sacramento County Garden Planner — Free
A 22-page printable planner built for Sacramento 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.