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When to Plant Coreopsis in Dixie, WA

Walla Walla County, Washington Zone 7a June

June to-do list for Walla Walla County, Washington

We've pulled the most time-sensitive tasks for Walla Walla County, Washington this June and put them front and centre. Tackle them in order.

Avg. last frost April 20
Avg. first frost October 15
Soil temp (4") 66°F
Watering Critical
Pest pressure High
Daylight 15.6 hrs
  1. Start coreopsis indoors

    Your window is short. These crops want several weeks of indoor growth before they go outside.

  2. Collect coreopsis at their peak

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

Get ahead of July
  • First harvests: coreopsis

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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.

Dixie, Washington is in USDA Zone 7a. The average last spring frost is April 20 and the first fall frost is October 15, giving you a growing season of approximately 178 days.

At an elevation of 3,151 feet, Walla Walla County receives approximately 23.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Coreopsis during the growing season.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Dixie, WA (Zone 7a) Moderate season
178 days
Last Spring Frost April 20
178 growing days
First Fall Frost October 15

Dixie Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.4

Drainage

Well Drained

Coreopsis Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Jan 30 Transplant: Apr 10 🌸 Bloom: Jun 12 – Oct 23
Recommended (50%) ✗ May not fit
Start indoors: Feb 16 Transplant: Apr 27 🌸 Bloom: Jun 29 – Nov 9
Safe Start (90%) ✗ May not fit
Start indoors: Mar 12 Transplant: May 21 🌸 Bloom: Jul 23 – Dec 3

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 Dixie

How your county's soil matches Coreopsis's growing requirements.

Soil pH

Your soil pH (5.2–6.4) overlaps with Coreopsis's range (5.5–7.5), though not a perfect match.

Soil Texture

The silt loam soil in Walla Walla County is excellent for Coreopsis — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.2%) — Coreopsis will thrive.

How to Plant Coreopsis

0.1"
Planting Depth
18"
Between Plants
24"
Between Rows

Succession Planting Coreopsis

3
successive plantings in your 178-day season

Sow every 6.9 weeks. Last sowing by Jul 27 to harvest before frost.

Coreopsis Water Budget

Plant needs
0.5″/week
Rainfall provides
0.6″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 2.9" 0" ❄️ Dormant
Feb 2.7" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 2.2" 1.7" 0.5" 💧 Light watering
May 2.2" 1.5" 0.7" 💧 Light watering
Jun 2.2" 1" 1.2" 🚿 Regular watering
Jul 2.2" 0.4" 1.8" 🚿 Regular watering
Aug 2.2" 0.5" 1.7" 🚿 Regular watering
Sep 2.2" 0.9" 1.3" 🚿 Regular watering
Oct 2.2" 2.2" 0" ✅ Rainfall sufficient
Nov 3.7" 0" ❄️ Dormant
Dec 3.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Walla Walla 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 needs ~962 GDD — county provides 2,447 GDD Excellent fit

Coreopsis Planting Timeline — Dixie, WA

Coreopsis Planting Calendar

Activity When Date Range
Start Indoors February 16 Feb 16 – Mar 2
Transplant Outdoors April 27 Apr 27 – May 11
Direct Sow April 20 Apr 20 – May 11
Bloom June 29 Jun 29 – Nov 9

Plant 0.1" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors
April Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June Bloom
July Bloom
August Bloom
September Bloom
October Bloom
November Bloom
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

60–80 days

🧪 Soil pH

Needs 5.5–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

178 days in Walla Walla County

Growing Tips for Coreopsis in Dixie

Direct sow Coreopsis outdoors after April 20 in Walla Walla 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.

Walla Walla County receives only 24" 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 →

🌱

Your Walla Walla County Garden Planner — Free

A 22-page printable planner built for Walla Walla County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Walla Walla County, WA. Local conditions may vary. Last updated: June 2026.