When to Plant Sunflower in Uinta County, WY
What to do in June
June is a pivotal month for Uinta County, Wyoming gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Transplant sunflower outside
Frost risk is low now in Uinta County, Wyoming. If you've been covering beds overnight, you can stop.
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Scatter sunflower into prepared beds
Keep the top inch of soil moist until germination — a gentle morning watering for 5–7 days does the job.
Looking ahead to July
- Starting indoors: sunflower
Sunflower (Helianthus annuus) is a fast-growing North American native annual famous for its towering stems and brilliant yellow heads. It thrives in full sun and heat, producing large, pollen-rich blooms that attract bees, butterflies, and seed-eating birds. Varieties range from 18-inch dwarfs to 12-foot giants and nearly every color except blue.
Uinta County, Wyoming is in USDA Zone 5a. The average last spring frost is June 17 and the first fall frost is August 31, giving you a growing season of approximately 75 days.
At an elevation of 5,768 feet, Uinta County receives approximately 23.5 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Sunflower to ensure they mature before fall.
Uinta County Soil Profile
Soil Type
Loam
Soil pH
6.3-8.3
Drainage
Well Drained
Sunflower 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 Uinta County
How your county's soil matches Sunflower's growing requirements.
Soil pH
Your soil pH (6.3–8.3) overlaps with Sunflower's range (6.0–7.5), though not a perfect match.
Soil Texture
The loam soil in Uinta County is excellent for Sunflower — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.2%). Annual compost additions will help Sunflower.
How to Plant Sunflower
Sunflower Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Sunflower
Sunflower 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 | Sunflower Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.5" | 0" | ❄️ Dormant |
| Feb | — | 1.3" | 0" | ❄️ Dormant |
| Mar | — | 2.2" | 0" | ❄️ Dormant |
| Apr | — | 2.8" | 0" | ❄️ Dormant |
| May | — | 2.7" | 0" | ❄️ Dormant |
| Jun | 2.2" | 1.8" | 0.4" | 💧 Light watering |
| Jul | 2.2" | 1.8" | 0.4" | 💧 Light watering |
| Aug | 2.2" | 2.2" | 0" | ✅ Rainfall sufficient |
| Sep | — | 2.2" | 0" | ❄️ Dormant |
| Oct | — | 1.9" | 0" | ❄️ Dormant |
| Nov | — | 1.7" | 0" | ❄️ Dormant |
| Dec | — | 1.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jun–Aug in Uinta County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Sunflower 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.
Sunflower Planting Timeline — Uinta County, WY
Sunflower Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | May 27 | May 27 – Jun 10 |
| Transplant Outdoors | June 24 | Jun 24 – Jul 8 |
| Direct Sow | June 24 | Jun 24 – Jul 15 |
| Bloom | September 16 | Sep 16 – Nov 25 |
Plant 1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Start Indoors |
| June | Start Indoors Transplant Outdoors Direct Sow |
| July | Transplant Outdoors Direct Sow |
| August | — |
| 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
70–100 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 5a
📆 Growing Season
75 days in Uinta County
Growing Tips for Sunflower in Uinta County
Direct sow Sunflower outdoors after June 17 in Uinta County when soil has warmed and frost danger has passed.
Your 75.0-day growing season in Uinta County is tight for Sunflower (70.0-100.0 days to maturity). Start indoors and choose early-maturing varieties.
Common pests for Sunflower in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.
Uinta County receives only 24" of rain annually. Sunflower needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Direct-sow 1 inch deep after last frost; germination takes 7-14 days at 65-75°F soil. Sunflowers dislike root disturbance so direct sowing is strongly preferred over transplanting. Plant in succession every 2 weeks for extended bloom. Stake tall varieties. Avoid overwatering — they tolerate drought once established. Birds will self-deadhead seed heads; leave them up through fall for wildlife.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Sunflower in Other Locations
Frequently Asked Questions
When should I plant Sunflower in Uinta County, WY?
Uinta County is in Zone 5a with an average last frost of June 17. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.
What planting zone is Uinta County, WY?
Uinta County, Wyoming is in USDA Hardiness Zone 5a. The average last spring frost is June 17 and first fall frost is August 31.
Your Uinta County Garden Planner — Free
A 22-page printable planner built for Uinta County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.