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When to plant Coreopsis in Oneida County County,

Oneida County County's 120-day season only supports one Coreopsis planting per year. Sow between May 30 and June 20 for the best chance at full maturity before September 20.

When to Plant Coreopsis in Oneida County, ID

Oneida County, Idaho Zone 6a June

Your June game plan for Oneida County, Idaho

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

Avg. last frost May 23
Avg. first frost September 20
Soil temp (4") 43°F
Watering Critical
Pest pressure High
Daylight 15.1 hrs
To set up a strong July, finish these tasks
  • Starting indoors: 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.

Oneida County, Idaho is in USDA Zone 6a. The average last spring frost is May 23 and the first fall frost is September 20, giving you a growing season of approximately 120 days.

At an elevation of 8,042 feet, Oneida County receives approximately 18.4 inches of rainfall annually with predominantly loam soil. Summer highs average 85°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.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Oneida County, ID (Zone 6a) Short season
120 days
Last Spring Frost May 23
120 growing days
First Fall Frost September 20

Oneida County Soil Profile

Soil Type

Loam

Soil pH

6.3-8.2

Drainage

Well Drained

Coreopsis Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 10 Transplant: May 19 🌸 Bloom: Jul 28 – Nov 17
Recommended (50%) ✗ May not fit
Start indoors: Mar 21 Transplant: May 30 🌸 Bloom: Aug 8 – Nov 28
Safe Start (90%) ✗ May not fit
Start indoors: Apr 13 Transplant: Jun 22 🌸 Bloom: Aug 31 – Dec 21

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 Oneida County

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

Soil pH

Your soil pH (6.3–8.2) overlaps with Coreopsis's range (5.5–7.5), though not a perfect match.

Soil Texture

The loam soil in Oneida 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

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

Succession Planting Coreopsis

2
successive plantings in your 120-day season

Sow every 6.9 weeks. Last sowing by Jul 02 to harvest before frost.

Coreopsis Water Budget

Plant needs
0.5″/week
Rainfall provides
0.6″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 8 gal / 100 sq ft
Drought risk

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 1.2" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 1.8" 0" ❄️ Dormant
Apr 1.8" 0" ❄️ Dormant
May 2.2" 2.1" 0.1" 💧 Light watering
Jun 2.2" 1.1" 1.1" 🚿 Regular watering
Jul 2.2" 1.8" 0.4" 💧 Light watering
Aug 2.2" 2" 0.2" 💧 Light watering
Sep 2.2" 1.7" 0.5" 💧 Light watering
Oct 1.7" 0" ❄️ Dormant
Nov 1.3" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Oneida 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 1,650 GDD Excellent fit

Coreopsis Planting Timeline — Oneida County, ID

Coreopsis Planting Calendar

Activity When Date Range
Start Indoors March 21 Mar 21 – Apr 4
Transplant Outdoors May 30 May 30 – Jun 13
Direct Sow May 30 May 30 – Jun 20
Bloom August 8 Aug 8 – Nov 28

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors
May Transplant Outdoors Direct Sow
June Transplant Outdoors Direct Sow
July
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 6a

📆 Growing Season

120 days in Oneida County

Growing Tips for Coreopsis in Oneida County

Direct sow Coreopsis outdoors after May 23 in Oneida 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.

Oneida County receives only 18" 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 →

Frequently Asked Questions

When should I plant Coreopsis in Oneida County, ID?

Oneida County is in Zone 6a with an average last frost of May 23. Plan your Coreopsis planting based on this frost date — see the calendar above for exact timing.

What planting zone is Oneida County, ID?

Oneida County, Idaho is in USDA Hardiness Zone 6a. The average last spring frost is May 23 and first fall frost is September 20.

When should I plant Coreopsis in Oneida County County, ?

In Oneida County County, , plant Coreopsis after the last frost (around May 23) and before the first frost (around September 20). Best results when soil holds above 50°F.

What growing zone is Oneida County County, for Coreopsis?

Oneida County County sits in USDA Zone 6a. Coreopsis grows reliably in zones 3a through 9b, so it's a good fit here.

Can Coreopsis grow in Oneida County County's climate?

Yes — Coreopsis grows well in Oneida County County's temperate climate. Oneida County County averages a 120-day frost-free season, with last frost around May 23 and first frost around September 20.

🌱

Your Oneida County Garden Planner — Free

A 22-page printable planner built for Oneida County (Zone 6a). 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 Oneida County, ID. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.