When to Plant Watercress in Rockingham County, NH
Top priorities for Rockingham County, New Hampshire gardeners in May
Your garden in Rockingham County, New Hampshire is working on a schedule, even when you're not. Here's where you should be this May.
-
Begin indoor sowing: watercress
Starting these indoors now means sturdy transplants ready the moment your soil warms up.
Get ahead of June
- First harvests: watercress
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.
Rockingham County, New Hampshire is in USDA Zone 6a. The average last spring frost is April 26 and the first fall frost is October 17, giving you a growing season of approximately 174 days.
At an elevation of 444 feet, Rockingham County receives approximately 50 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Watercress to ensure they mature before fall.
Rockingham County Soil Profile
Soil Type
Silt Loam
Soil pH
5.2-6.4
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 Rockingham County
How your county's soil matches Watercress's growing requirements.
Soil pH
Your soil pH (5.2–6.4) is more acidic than Watercress prefers (6.5–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Rockingham County is excellent for Watercress — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.3%). 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 Aug 18 to harvest before frost.
For a dedicated fall crop, sow by Aug 08.
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 | — | 3.8" | 0" | ❄️ Dormant |
| Feb | — | 3.1" | 0" | ❄️ Dormant |
| Mar | — | 4.2" | 0" | ❄️ Dormant |
| Apr | 6.5" | 3.9" | 2.6" | 💧 Light watering |
| May | 6.5" | 5" | 1.5" | 💧 Light watering |
| Jun | 6.5" | 4.9" | 1.6" | 💧 Light watering |
| Jul | 6.5" | 4.3" | 2.2" | 💧 Light watering |
| Aug | 6.5" | 4.6" | 1.9" | 💧 Light watering |
| Sep | 6.5" | 4.5" | 2" | 💧 Light watering |
| Oct | 6.5" | 4.4" | 2.1" | 💧 Light watering |
| Nov | — | 3.5" | 0" | ❄️ Dormant |
| Dec | — | 4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Rockingham 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 — Rockingham County, NH
Watercress Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 22 | Mar 22 – Apr 5 |
| Transplant Outdoors | April 26 | Apr 26 – May 10 |
| Direct Sow | April 12 | Apr 12 – May 3 |
| Harvest | June 7 | Jun 7 – Jul 12 |
| Fall Sowing | August 8 | Aug 8 – Aug 22 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1.5"/week · Only during dry spells
📅 Days to Maturity
40–60 days
🧪 Soil pH
Needs 6.5–7.5 · Your soil: too_acidic
🗺️ USDA Zone
Zone 6a
📆 Growing Season
174 days in Rockingham County
Growing Tips for Watercress in Rockingham County
Direct sow Watercress outdoors after April 26 in Rockingham County when soil has warmed and frost danger has passed.
Your generous 174.0-day season in Rockingham 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 Rockingham County, NH?
Rockingham County is in Zone 6a with an average last frost of April 26. Plan your Watercress planting based on this frost date — see the calendar above for exact timing.
What planting zone is Rockingham County, NH?
Rockingham County, New Hampshire is in USDA Hardiness Zone 6a. The average last spring frost is April 26 and first fall frost is October 17.
Your Rockingham County Garden Planner — Free
A 24-page printable planner built for Rockingham County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.