When to plant Coreopsis in Samoa, CA
The best window to plant Coreopsis in Samoa, is February 6–February 27, when soil warms to 50°F. Last frost typically hits February 27; first frost November 28.
When to Plant Coreopsis in Samoa, CA
Your June game plan for Humboldt County, California
Your Humboldt County, California garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.
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Pick coreopsis
If you can't use it all right away, check the food-preservation section of your planner.
A few tasks this June that'll pay off in 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.
Samoa, California is in USDA Zone 9b. The average last spring frost is February 27 and the first fall frost is November 28, giving you a growing season of approximately 274 days.
At an elevation of 148 feet, Humboldt County receives approximately 22.1 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 87°F, providing good warmth for Coreopsis during the growing season. Sandy soil warms quickly in spring — great for early planting — but Coreopsis will need more frequent watering and organic matter to retain nutrients.
Samoa Soil Profile
Soil Type
Sandy Loam
Soil pH
6.2-6.8
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 Samoa
How your county's soil matches Coreopsis's growing requirements.
Soil pH
Your soil pH (6.2–6.8) is within Coreopsis's preferred range (5.5–7.5).
Soil Texture
Sandy soil in Humboldt County warms quickly in spring but drains fast. Coreopsis will need more frequent watering and regular compost additions to retain nutrients.
Organic Matter
Organic matter is moderate (2.3%). Annual compost additions will help Coreopsis.
How to Plant Coreopsis
Succession Planting Coreopsis
Sow every 6.9 weeks. Last sowing by Sep 09 to harvest before frost.
Coreopsis Water Budget
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 | — | 4.8" | 0" | ❄️ Dormant |
| Feb | 2.2" | 5" | 0" | ✅ Rainfall sufficient |
| Mar | 2.2" | 3.3" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 1.7" | 0.5" | 💧 Light watering |
| May | 2.2" | 0.5" | 1.7" | 🚿 Regular watering |
| Jun | 2.2" | 0.1" | 2.1" | 🚿 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" | 0.8" | 1.4" | 🚿 Regular watering |
| Nov | 2.2" | 1.9" | 0.3" | 💧 Light watering |
| Dec | — | 3.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Feb–Nov in Humboldt 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 — Samoa, CA
Coreopsis Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 2 | Jan 2 – Jan 16 |
| Transplant Outdoors | February 13 | Feb 13 – Feb 27 |
| Direct Sow | February 6 | Feb 6 – Feb 27 |
| Bloom | April 10 | Apr 10 – Sep 11 |
Plant 0.1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Transplant Outdoors Direct Sow |
| March | — |
| April | Bloom |
| May | Bloom |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | — |
| November | — |
| 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: ideal
🗺️ USDA Zone
Zone 9b
📆 Growing Season
274 days in Humboldt County
Growing Tips for Coreopsis in Samoa
Direct sow Coreopsis outdoors after February 27 in Humboldt County when soil has warmed and frost danger has passed.
Sandy soil in Humboldt County dries quickly — mulch Coreopsis with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
Common pests for Coreopsis in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.
Humboldt County receives only 22" 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
When should I plant Coreopsis in Samoa, CA?
In Samoa, CA, plant Coreopsis after the last frost (around February 27) and before the first frost (around November 28). Best results when soil holds above 50°F.
What growing zone is Samoa, CA for Coreopsis?
Samoa sits in USDA Zone 9b. Coreopsis grows reliably in zones 3a through 9b, so it's a good fit here.
Can Coreopsis grow in Samoa's climate?
Yes — Coreopsis grows well in Samoa's temperate climate. Samoa averages a 275-day frost-free season, with last frost around February 27 and first frost around November 28.
Your Humboldt County Garden Planner — Free
A 22-page printable planner built for Humboldt 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.