When to Plant Watercress in King William County, VA
Watercress is a semi-aquatic plant with a peppery, tangy flavor rich in vitamins and minerals. It grows naturally along streams and can be cultivated in containers with standing water.
King William County, Virginia is in USDA Zone 7a. The average last spring frost is April 6 and the first fall frost is November 2, giving you a growing season of approximately 210 days.
At an elevation of 110 feet, King William County receives approximately 40.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 94°F, providing good warmth for Watercress during the growing season.
King William County Soil Profile
Soil Type
Silt Loam
Soil pH
5.3-7
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 King William County
How your county's soil matches Watercress's growing requirements.
Soil pH
Your soil pH (5.3–7.0) is more acidic than Watercress prefers (6.5–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in King William County is excellent for Watercress — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.8%). Annual compost additions will help Watercress.
How to Plant Watercress
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Watercress
Sow every 4.6 weeks. Last sowing by Sep 03 to harvest before frost.
For a dedicated fall crop, sow by Aug 24.
Plant Water Budget
Monthly Watering Guide for Watercress
Watercress 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 | Watercress Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 3.2" | 0" | ❄️ Dormant |
| Feb | — | 3.3" | 0" | ❄️ Dormant |
| Mar | — | 3.5" | 0" | ❄️ Dormant |
| Apr | 6.5" | 2.8" | 3.7" | 🚿 Regular watering |
| May | 6.5" | 3.7" | 2.8" | 💧 Light watering |
| Jun | 6.5" | 3.5" | 3" | 💧 Light watering |
| Jul | 6.5" | 3.8" | 2.7" | 💧 Light watering |
| Aug | 6.5" | 4.5" | 2" | 💧 Light watering |
| Sep | 6.5" | 3" | 3.5" | 🚿 Regular watering |
| Oct | 6.5" | 2.3" | 4.2" | 🚿 Regular watering |
| Nov | 6.5" | 3.3" | 3.2" | 💧 Light watering |
| Dec | — | 3.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Nov in King William County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Watercress 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.
Watercress Planting Timeline — King William County, VA
Watercress Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 2 | Mar 2 – Mar 16 |
| Transplant Outdoors | April 6 | Apr 6 – Apr 20 |
| Direct Sow | March 23 | Mar 23 – Apr 13 |
| Harvest | May 18 | May 18 – Jun 22 |
| Fall Sowing | August 24 | Aug 24 – Sep 7 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | Harvest |
| June | Harvest |
| July | — |
| August | Fall Sowing |
| September | Fall Sowing |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1.5"/week · 1-2 times/week
📅 Days to Maturity
40–60 days
🧪 Soil pH
Needs 6.5–7.5 · Your soil: too_acidic
🗺️ USDA Zone
Zone 7a
📆 Growing Season
210 days in King William County
Growing Tips for Watercress in King William County
Direct sow Watercress outdoors after April 06 in King William County when soil has warmed and frost danger has passed.
Your generous 210.0-day season in King William County allows multiple plantings of Watercress. Sow every 20.0 days for continuous harvest.
Common pests for Watercress in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
Grow in containers with trays of water kept fresh. Provide partial shade and cool conditions. Harvest stems by cutting above water level. Replace water frequently to prevent stagnation.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Watercress in Other Locations
Frequently Asked Questions
When should I plant Watercress in King William County, VA?
King William County is in Zone 7a with an average last frost of April 6. Plan your Watercress planting based on this frost date — see the calendar above for exact timing.
What planting zone is King William County, VA?
King William County, Virginia is in USDA Hardiness Zone 7a. The average last spring frost is April 6 and first fall frost is November 2.
Plan Your Garden with Confidence
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