When to plant Sweet Corn in Compton, MD
The best window to plant Sweet Corn in Compton, is April 12–May 3, when soil warms to 50°F. Last frost typically hits April 5; first frost November 4.
When to Plant Sweet Corn in Compton, MD
St. Mary's County, Maryland gardeners: here's your July plan
If you only do a handful of things in the garden this July, make it these. They're sequenced around your zone's frost timing.
Sweet corn is bred for high sugar content in its kernels, which convert to starch rapidly after harvest. Modern supersweet varieties hold their sweetness longer.
Compton, Maryland is in USDA Zone 8a. The average last spring frost is April 5 and the first fall frost is November 4, giving you a growing season of approximately 213 days.
At an elevation of 156 feet, St. Mary's County receives approximately 41.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 92°F, providing good warmth for Sweet Corn during the growing season.
Compton Soil Profile
Soil Type
Silt Loam
Soil pH
5.5-6.9
Drainage
Well Drained
Sweet Corn 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 Compton
How your county's soil matches Sweet Corn's growing requirements.
Soil pH
Your soil pH (5.5–6.9) overlaps with Sweet Corn's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in St. Mary's County is excellent for Sweet Corn — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.0%). Annual compost additions will help Sweet Corn.
How to Plant Sweet Corn
Succession Planting Sweet Corn
Sow every 6.9 weeks. Last sowing by Aug 06 to harvest before frost.
Sweet Corn Water Budget
Monthly Watering Guide for Sweet Corn
Sweet Corn needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.
| Month | Sweet Corn Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 3.1" | 0" | ❄️ Dormant |
| Feb | — | 2.6" | 0" | ❄️ Dormant |
| Mar | — | 3.3" | 0" | ❄️ Dormant |
| Apr | 6.5" | 3.3" | 3.2" | 💧 Light watering |
| May | 6.5" | 3.9" | 2.6" | 💧 Light watering |
| Jun | 6.5" | 4.3" | 2.2" | 💧 Light watering |
| Jul | 6.5" | 4" | 2.5" | 💧 Light watering |
| Aug | 6.5" | 4.3" | 2.2" | 💧 Light watering |
| Sep | 6.5" | 3.6" | 2.9" | 💧 Light watering |
| Oct | 6.5" | 3.4" | 3.1" | 💧 Light watering |
| Nov | 6.5" | 2.7" | 3.8" | 🚿 Regular watering |
| Dec | — | 2.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Nov in St. Mary's County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Sweet Corn 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.
Sweet Corn Planting Timeline — Compton, MD
Sweet Corn Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | April 12 | Apr 12 – May 3 |
| Harvest | June 14 | Jun 14 – Jul 26 |
Plant 1" deep · 12" apart · Rows 36" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Direct Sow |
| May | Direct Sow |
| June | Harvest |
| July | Harvest |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1.5"/week · 1-2 times/week
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 8a
📆 Growing Season
213 days in St. Mary's County
Growing Tips for Sweet Corn in Compton
Direct sow Sweet Corn outdoors after April 05 in St. Mary's County when soil has warmed and frost danger has passed.
Common pests for Sweet Corn in this region include corn earworm and corn borers. Use row covers early in the season and inspect plants weekly.
General growing tips
Plant in blocks of at least 4 rows for wind pollination. Direct sow after soil is warm. Isolate supersweet varieties from other corn types to prevent cross-pollination.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Sweet Corn in Other Locations
When should I plant Sweet Corn in Compton, MD?
In Compton, MD, plant Sweet Corn after the last frost (around April 5) and before the first frost (around November 4). Best results when soil holds above 50°F.
What growing zone is Compton, MD for Sweet Corn?
Compton sits in USDA Zone 8a. Sweet Corn grows reliably in zones 3a through 11b, so it's a good fit here.
Can Sweet Corn grow in Compton's climate?
Yes — Sweet Corn grows well in Compton's temperate climate. Compton averages a 213-day frost-free season, with last frost around April 5 and first frost around November 4.
Your St. Mary's County Garden Planner — Free
A 22-page printable planner built for St. Mary's County (Zone 8a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.