When to Plant Watercress in Dyer County, TN
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.
Dyer County, Tennessee is in USDA Zone 7a. The average last spring frost is April 2 and the first fall frost is October 28, giving you a growing season of approximately 209 days.
At an elevation of 1,191 feet, Dyer County receives approximately 51.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 92°F, providing good warmth for Watercress during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Watercress root diseases.
Dyer County Soil Profile
Soil Type
Silt Loam
Soil pH
5.7-6.5
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 Dyer County
How your county's soil matches Watercress's growing requirements.
Soil pH
Your soil pH (5.7–6.5) is more acidic than Watercress prefers (6.5–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Dyer County is excellent for Watercress — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.2%). 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 29 to harvest before frost.
For a dedicated fall crop, sow by Aug 19.
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 | — | 4.8" | 0" | ❄️ Dormant |
| Feb | — | 3.5" | 0" | ❄️ Dormant |
| Mar | — | 5.4" | 0" | ❄️ Dormant |
| Apr | 6.5" | 3.6" | 2.9" | 💧 Light watering |
| May | 6.5" | 4.3" | 2.2" | 💧 Light watering |
| Jun | 6.5" | 4" | 2.5" | 💧 Light watering |
| Jul | 6.5" | 4.8" | 1.7" | 💧 Light watering |
| Aug | 6.5" | 4.7" | 1.8" | 💧 Light watering |
| Sep | 6.5" | 4.1" | 2.4" | 💧 Light watering |
| Oct | 6.5" | 3.6" | 2.9" | 💧 Light watering |
| Nov | — | 4" | 0" | ❄️ Dormant |
| Dec | — | 4.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Dyer 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 — Dyer County, TN
Watercress Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 26 | Feb 26 – Mar 12 |
| Transplant Outdoors | April 2 | Apr 2 – Apr 16 |
| Direct Sow | March 19 | Mar 19 – Apr 9 |
| Harvest | May 14 | May 14 – Jun 18 |
| Fall Sowing | August 19 | Aug 19 – Sep 2 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| 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
209 days in Dyer County
Growing Tips for Watercress in Dyer County
Direct sow Watercress outdoors after April 02 in Dyer County when soil has warmed and frost danger has passed.
Your generous 209.0-day season in Dyer 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 Dyer County, TN?
Dyer County is in Zone 7a with an average last frost of April 2. Plan your Watercress planting based on this frost date — see the calendar above for exact timing.
What planting zone is Dyer County, TN?
Dyer County, Tennessee is in USDA Hardiness Zone 7a. The average last spring frost is April 2 and first fall frost is October 28.
Plan Your Garden with Confidence
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