When to Plant Coreopsis in Sumner, NE
Your July gardening checklist
We've pulled the most time-sensitive tasks for Dawson County, Nebraska this July and put them front and centre. Tackle them in order.
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Start coreopsis indoors
Label every cell. You will absolutely forget which is which otherwise.
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Basket week: coreopsis
If you can't use it all right away, check the food-preservation section of your planner.
Looking ahead to August
- 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.
Sumner, Nebraska is in USDA Zone 5b. The average last spring frost is May 5 and the first fall frost is October 3, giving you a growing season of approximately 151 days.
At an elevation of 790 feet, Dawson County receives approximately 21.8 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Coreopsis during the growing season.
Sumner Soil Profile
Soil Type
Loam
Soil pH
6.7-7.8
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 Sumner
How your county's soil matches Coreopsis's growing requirements.
Soil pH
Your soil pH (6.7–7.8) overlaps with Coreopsis's range (5.5–7.5), though not a perfect match.
Soil Texture
The loam soil in Dawson County is excellent for Coreopsis — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.5%). Annual compost additions will help Coreopsis.
How to Plant Coreopsis
Succession Planting Coreopsis
Sow every 6.9 weeks. Last sowing by Jul 15 to harvest before frost.
Coreopsis Water Budget
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 | — | 0.6" | 0" | ❄️ Dormant |
| Feb | — | 0.7" | 0" | ❄️ Dormant |
| Mar | — | 1.2" | 0" | ❄️ Dormant |
| Apr | — | 2.6" | 0" | ❄️ Dormant |
| May | 2.2" | 3.1" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 3.3" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 3" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 2.9" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 1.8" | 0.4" | 💧 Light watering |
| Oct | 2.2" | 1.3" | 0.9" | 💧 Light watering |
| Nov | — | 0.8" | 0" | ❄️ Dormant |
| Dec | — | 0.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Dawson 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 — Sumner, NE
Coreopsis Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 3 | Mar 3 – Mar 17 |
| Transplant Outdoors | May 19 | May 19 – Jun 2 |
| Direct Sow | May 12 | May 12 – Jun 2 |
| Bloom | July 28 | Jul 28 – Nov 10 |
Plant 0.1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | — |
| May | Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| 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 5b
📆 Growing Season
151 days in Dawson County
Growing Tips for Coreopsis in Sumner
Direct sow Coreopsis outdoors after May 05 in Dawson 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.
Dawson 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
Your Dawson County Garden Planner — Free
A 22-page printable planner built for Dawson County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.