When to Plant Cowpeas in Fairfax County, VA
What to do in May
May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Fairfax County, Virginia.
June will be here before you know it — start on
- First harvests: cowpeas
Cowpeas (black-eyed peas) are a heat-loving legume that fixes nitrogen in the soil. They are drought-tolerant and produce protein-rich pods in hot conditions.
Fairfax County, Virginia is in USDA Zone 7b. The average last spring frost is April 6 and the first fall frost is November 3, giving you a growing season of approximately 211 days.
At an elevation of 548 feet, Fairfax County receives approximately 53 inches of rainfall annually with predominantly silt loam soil. Summer highs average 93°F, providing good warmth for Cowpeas during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Cowpeas root diseases.
Fairfax County Soil Profile
Soil Type
Silt Loam
Soil pH
5.4-6.5
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 Fairfax County
How your county's soil matches Cowpeas's growing requirements.
Soil pH
Your soil pH (5.4–6.5) overlaps with Cowpeas's range (5.5–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Fairfax County is excellent for Cowpeas — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.8%). Annual compost additions will help Cowpeas.
How to Plant Cowpeas
Succession Planting Cowpeas
Sow every 6.9 weeks. Last sowing by Aug 05 to harvest before frost.
Plant Water Budget
Monthly Watering Guide for Cowpeas
Cowpeas 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 | Cowpeas Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 4.1" | 0" | ❄️ Dormant |
| Feb | — | 4.6" | 0" | ❄️ Dormant |
| Mar | — | 5.5" | 0" | ❄️ Dormant |
| Apr | 2.2" | 4.1" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 3.8" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 5" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 5.9" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 4.1" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3.8" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 3.3" | 0" | ✅ Rainfall sufficient |
| Nov | 2.2" | 4.4" | 0" | ✅ Rainfall sufficient |
| Dec | — | 4.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Nov in Fairfax County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Cowpeas 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.
Cowpeas Planting Timeline — Fairfax County, VA
Cowpeas Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | April 13 | Apr 13 – May 4 |
| Harvest | June 15 | Jun 15 – Jul 27 |
Plant 1" deep · 15" apart · Rows 24" 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
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 5.5–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 7b
📆 Growing Season
211 days in Fairfax County
Growing Tips for Cowpeas in Fairfax County
Direct sow Cowpeas outdoors after April 06 in Fairfax County when soil has warmed and frost danger has passed.
Common pests for Cowpeas in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.
General growing tips
Direct sow after soil is thoroughly warm. Do not over-fertilize with nitrogen as cowpeas fix their own. Harvest pods when they begin to dry on the vine for dry beans.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Cowpeas in Other Locations
Frequently Asked Questions
When should I plant Cowpeas in Fairfax County, VA?
Fairfax County is in Zone 7b with an average last frost of April 6. Plan your Cowpeas planting based on this frost date — see the calendar above for exact timing.
What planting zone is Fairfax County, VA?
Fairfax County, Virginia is in USDA Hardiness Zone 7b. The average last spring frost is April 6 and first fall frost is November 3.
Your Fairfax County Garden Planner — Free
A 24-page printable planner built for Fairfax County (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.