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When to Plant Coreopsis in Cavalier County, ND

Cavalier County, North Dakota Zone 3b June

Cavalier County, North Dakota gardeners: here's your June plan

Here's what deserves your attention in Cavalier County, North Dakota this month. Everything below is tailored to Zone 3b and timed around your local frost dates.

Avg. last frost May 13
Avg. first frost September 28
Soil temp (4") 61°F
Watering Low
Pest pressure Moderate
Daylight 15.9 hrs
A few tasks this June that'll pay off in July
  • 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.

Cavalier County, North Dakota is in USDA Zone 3b. The average last spring frost is May 13 and the first fall frost is September 28, giving you a growing season of approximately 138 days.

At an elevation of 568 feet, Cavalier County receives approximately 27.9 inches of rainfall annually with predominantly loam soil. Summer highs average 78°F, so choose short-season varieties of Coreopsis to ensure they mature before fall.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Cavalier County, ND (Zone 3b) Short season
138 days
Last Spring Frost May 13
138 growing days
First Fall Frost September 28

Cavalier County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.4

Drainage

Well Drained

Coreopsis Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 28 Transplant: May 23 🌸 Bloom: Aug 15 – Oct 17
Recommended (50%) ✗ May not fit
Start indoors: Mar 4 Transplant: May 27 🌸 Bloom: Aug 19 – Oct 21
Safe Start (90%) ✗ May not fit
Start indoors: Mar 18 Transplant: Jun 10 🌸 Bloom: Sep 2 – Nov 4

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 Cavalier County

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

Soil pH

Your soil pH (6.7–7.4) is within Coreopsis's preferred range (5.5–7.5).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.3%) — Coreopsis will thrive.

How to Plant Coreopsis

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

Succession Planting Coreopsis

2
successive plantings in your 138-day season

Sow every 6.9 weeks. Last sowing by Jul 10 to harvest before frost.

Coreopsis Water Budget

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

Water stress score is 6/10 — 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 0.8" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 2.8" 0" ❄️ Dormant
May 2.2" 4.7" 0" ✅ Rainfall sufficient
Jun 2.2" 4.4" 0" ✅ Rainfall sufficient
Jul 2.2" 3.8" 0" ✅ Rainfall sufficient
Aug 2.2" 2.9" 0" ✅ Rainfall sufficient
Sep 2.2" 2.9" 0" ✅ Rainfall sufficient
Oct 1.6" 0" ❄️ Dormant
Nov 0.9" 0" ❄️ Dormant
Dec 0.6" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Cavalier 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 ~595 GDD — county provides 1,173 GDD Excellent fit

Coreopsis Planting Timeline — Cavalier County, ND

Coreopsis Planting Calendar

Activity When Date Range
Start Indoors March 4 Mar 4 – Mar 18
Transplant Outdoors May 27 May 27 – Jun 10
Direct Sow May 20 May 20 – Jun 10
Bloom August 19 Aug 19 – Oct 21

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 3b

📆 Growing Season

138 days in Cavalier County

Growing Tips for Coreopsis in Cavalier County

Direct sow Coreopsis outdoors after May 13 in Cavalier 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 →

Frequently Asked Questions

When should I plant Coreopsis in Cavalier County, ND?

Cavalier County is in Zone 3b with an average last frost of May 13. Plan your Coreopsis planting based on this frost date — see the calendar above for exact timing.

What planting zone is Cavalier County, ND?

Cavalier County, North Dakota is in USDA Hardiness Zone 3b. The average last spring frost is May 13 and first fall frost is September 28.

🌱

Your Cavalier County Garden Planner — Free

A 22-page printable planner built for Cavalier County (Zone 3b). 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 Cavalier County, ND. 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.