When to Plant Lettuce in Penobscot County, ME
What to do in May
May is a pivotal month for Penobscot County, Maine gardens. Focus on these tasks first and you'll set up the rest of the season for success.
-
Move lettuce into the garden
Your last frost (May 10) has passed. These warm-season crops can handle outdoor soil now.
To set up a strong June, finish these tasks
- Starting indoors: lettuce
- First harvests: lettuce
Lettuce is a fast-growing cool-season green available in leaf, romaine, butterhead, and crisphead types. It is the foundation of salads and one of the easiest crops to grow.
Penobscot County, Maine is in USDA Zone 5a. The average last spring frost is May 10 and the first fall frost is October 2, giving you a growing season of approximately 145 days.
At an elevation of 842 feet, Penobscot County receives approximately 38.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Lettuce to ensure they mature before fall.
Penobscot County Soil Profile
Soil Type
Silt Loam
Soil pH
4.8-6.7
Drainage
Well Drained
Plant 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 Penobscot County
How your county's soil matches Lettuce's growing requirements.
Soil pH
Your soil pH (4.8–6.7) is more acidic than Lettuce prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Penobscot County is excellent for Lettuce — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.6%). Annual compost additions will help Lettuce.
How to Plant Lettuce
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Lettuce
Sow every 3.4 weeks. Last sowing by Aug 03 to harvest before frost.
For a dedicated fall crop, sow by Jul 24.
Plant Water Budget
Monthly Watering Guide for Lettuce
Lettuce needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.
| Month | Lettuce Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 2.4" | 0" | ❄️ Dormant |
| Feb | — | 2.3" | 0" | ❄️ Dormant |
| Mar | — | 3" | 0" | ❄️ Dormant |
| Apr | — | 3.4" | 0" | ❄️ Dormant |
| May | 3" | 3.9" | 0" | ✅ Rainfall sufficient |
| Jun | 3" | 3.9" | 0" | ✅ Rainfall sufficient |
| Jul | 3" | 3.5" | 0" | ✅ Rainfall sufficient |
| Aug | 3" | 3.2" | 0" | ✅ Rainfall sufficient |
| Sep | 3" | 3.7" | 0" | ✅ Rainfall sufficient |
| Oct | 3" | 3.6" | 0" | ✅ Rainfall sufficient |
| Nov | — | 3.2" | 0" | ❄️ Dormant |
| Dec | — | 2.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Penobscot County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Lettuce 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.
Lettuce Planting Timeline — Penobscot County, ME
Lettuce Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 5 | Apr 5 – Apr 19 |
| Transplant Outdoors | May 10 | May 10 – May 24 |
| Direct Sow | April 26 | Apr 26 – May 17 |
| Harvest | June 14 | Jun 14 – Aug 23 |
| Fall Sowing | July 24 | Jul 24 – Aug 7 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Fall Sowing Harvest |
| August | Fall Sowing Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.7"/week · Natural rainfall sufficient
📅 Days to Maturity
30–60 days
🧪 Soil pH
Needs 6–7 · Your soil: too_acidic
🗺️ USDA Zone
Zone 5a
📆 Growing Season
145 days in Penobscot County
Growing Tips for Lettuce in Penobscot County
Direct sow Lettuce outdoors after May 10 in Penobscot County when soil has warmed and frost danger has passed.
Common pests for Lettuce in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.
General growing tips
Sow seeds directly every 2 weeks for continuous harvest. Provide afternoon shade in warm weather to delay bolting. Harvest in the morning for crispest leaves.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Very easy to save. Let a few plants bolt each season.
Lettuce in Other Locations
Frequently Asked Questions
When should I plant Lettuce in Penobscot County, ME?
Penobscot County is in Zone 5a with an average last frost of May 10. Plan your Lettuce planting based on this frost date — see the calendar above for exact timing.
What planting zone is Penobscot County, ME?
Penobscot County, Maine is in USDA Hardiness Zone 5a. The average last spring frost is May 10 and first fall frost is October 2.
Your Penobscot County Garden Planner — Free
A 24-page printable planner built for Penobscot 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.