When to plant Sunflower in Rice County, MN
For Sunflower in Rice County, the safe spring window opens around May 7 and closes around May 28. Last expected frost is April 30, first fall frost October 7, giving a 160-day growing season.
When to Plant Sunflower in Rice County, MN
Your July game plan for Rice County, Minnesota
We've pulled the most time-sensitive tasks for Rice County, Minnesota this July and put them front and centre. Tackle them in order.
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Collect sunflower at their peak
Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.
August prep starts now
- First harvests: 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.
Rice County, Minnesota is in USDA Zone 4b. The average last spring frost is April 30 and the first fall frost is October 7, giving you a growing season of approximately 160 days.
At an elevation of 873 feet, Rice County receives approximately 36.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Sunflower to ensure they mature before fall.
Rice County Soil Profile
Soil Type
Silt Loam
Soil pH
6.2-7.1
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 Rice County
How your county's soil matches Sunflower's growing requirements.
Soil pH
Your soil pH (6.2–7.1) is within Sunflower's preferred range (6.0–7.5).
Soil Texture
The silt loam soil in Rice County is excellent for Sunflower — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.9%) — Sunflower will thrive.
How to Plant Sunflower
Succession Planting Sunflower
Sow every 8 weeks. Last sowing by Jun 29 to harvest before frost.
Sunflower Water Budget
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 | — | 1.8" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.7" | 0" | ❄️ Dormant |
| Apr | 2.2" | 3.4" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 3.7" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4.1" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 4.1" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 4" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3.6" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 3.2" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.4" | 0" | ❄️ Dormant |
| Dec | — | 2.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Rice 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 — Rice County, MN
Sunflower Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 9 | Apr 9 – Apr 23 |
| Transplant Outdoors | May 7 | May 7 – May 21 |
| Direct Sow | May 7 | May 7 – May 28 |
| Bloom | July 30 | Jul 30 – Oct 1 |
Plant 1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Bloom |
| 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
70–100 days
🧪 Soil pH
Needs 6–7.5 · Your soil: ideal
🗺️ USDA Zone
Zone 4b
📆 Growing Season
160 days in Rice County
Growing Tips for Sunflower in Rice County
Direct sow Sunflower outdoors after April 30 in Rice County when soil has warmed and frost danger has passed.
Common pests for Sunflower in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.
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 Rice County, MN?
Rice County is in Zone 4b with an average last frost of April 30. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.
What planting zone is Rice County, MN?
Rice County, Minnesota is in USDA Hardiness Zone 4b. The average last spring frost is April 30 and first fall frost is October 7.
When should I plant Sunflower in Rice County, MN?
In Rice County, MN, plant Sunflower after the last frost (around April 30) and before the first frost (around October 7). Best results when soil holds above 50°F.
What growing zone is Rice County, MN for Sunflower?
Rice County sits in USDA Zone 4b. Sunflower grows reliably in zones 2a through 11b, so it's a good fit here.
Can Sunflower grow in Rice County's climate?
Yes — Sunflower grows well in Rice County's temperate climate. Rice County averages a 160-day frost-free season, with last frost around April 30 and first frost around October 7.
Your Rice County Garden Planner — Free
A 22-page printable planner built for Rice County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.