When to plant Sunflower in Waldo County, ME
For Sunflower in Waldo County, the safe spring window opens around May 15 and closes around June 5. Last expected frost is May 8, first fall frost October 6, giving a 151-day growing season.
When to Plant Sunflower in Waldo County, ME
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.
Waldo County, Maine is in USDA Zone 5b. The average last spring frost is May 8 and the first fall frost is October 6, giving you a growing season of approximately 151 days.
At an elevation of 966 feet, Waldo County receives approximately 46 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.
Waldo County Soil Profile
Soil Type
Silt Loam
Soil pH
4.8-6.7
Drainage
Well Drained
Monthly Watering Guide for Sunflower
Sunflower needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Sunflower Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 3.1" | 0" | ❄️ Dormant |
| Feb | — | 2.7" | 0" | ❄️ Dormant |
| Mar | — | 4.4" | 0" | ❄️ Dormant |
| Apr | — | 4.1" | 0" | ❄️ Dormant |
| May | 4.3" | 4.8" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Jul | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Sep | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Oct | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Nov | — | 4" | 0" | ❄️ Dormant |
| Dec | — | 3.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Waldo County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Sunflower Planting Timeline — Waldo County, ME
Sunflower Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 17 | Apr 17 – May 1 |
| Transplant Outdoors | May 15 | May 15 – May 29 |
| Direct Sow | May 15 | May 15 – Jun 5 |
| Bloom | August 7 | Aug 7 – Oct 23 |
Plant 1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Start Indoors Transplant Outdoors Direct Sow |
| June | Direct Sow |
| July | — |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Low — drought tolerant
📅 Days to Maturity
70–100 days
🧪 Soil pH
Needs 6–7.5 · Your soil: N/A
🗺️ USDA Zone
Zone 5b
📆 Growing Season
151 days in Waldo County
Growing Tips for Waldo County
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 Waldo County, ME?
Waldo County is in Zone 5b with an average last frost of May 8. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.
What planting zone is Waldo County, ME?
Waldo County, Maine is in USDA Hardiness Zone 5b. The average last spring frost is May 8 and first fall frost is October 6.
When should I plant Sunflower in Waldo County, ME?
In Waldo County, ME, plant Sunflower after the last frost (around May 8) and before the first frost (around October 6). Best results when soil holds above 50°F.
What growing zone is Waldo County, ME for Sunflower?
Waldo County sits in USDA Zone 5b. Sunflower grows reliably in zones 2a through 11b, so it's a good fit here.
Can Sunflower grow in Waldo County's climate?
Yes — Sunflower grows well in Waldo County's temperate climate. Waldo County averages a 151-day frost-free season, with last frost around May 8 and first frost around October 6.
Your Waldo County Garden Planner — Free
A 22-page printable planner built for Waldo 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.