When to Plant Watercress in Adair County, OK
May in Adair County, Oklahoma — your action list
Here's what deserves your attention in Adair County, Oklahoma this month. Everything below is tailored to Zone 7b and timed around your local frost dates.
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Get watercress seeds going inside
Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.
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Pick watercress
If you can't use it all right away, check the food-preservation section of your planner.
June will be here before you know it — start on
- 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.
Adair County, Oklahoma is in USDA Zone 7b. The average last spring frost is April 7 and the first fall frost is October 27, giving you a growing season of approximately 203 days.
At an elevation of 486 feet, Adair County receives approximately 33.9 inches of rainfall annually with predominantly loam soil. Summer highs average 93°F, providing good warmth for Watercress during the growing season.
Adair County Soil Profile
Soil Type
Loam
Soil pH
6.7-7.1
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 Adair County
How your county's soil matches Watercress's growing requirements.
Soil pH
Your soil pH (6.7–7.1) is within Watercress's preferred range (6.5–7.5).
Soil Texture
The loam soil in Adair County is excellent for Watercress — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.1%) — Watercress will thrive.
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 28 to harvest before frost.
For a dedicated fall crop, sow by Aug 18.
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 | — | 1" | 0" | ❄️ Dormant |
| Feb | — | 1.2" | 0" | ❄️ Dormant |
| Mar | — | 2.4" | 0" | ❄️ Dormant |
| Apr | 6.5" | 4.2" | 2.3" | 💧 Light watering |
| May | 6.5" | 4.5" | 2" | 💧 Light watering |
| Jun | 6.5" | 5.5" | 1" | 💧 Light watering |
| Jul | 6.5" | 4.1" | 2.4" | 💧 Light watering |
| Aug | 6.5" | 3.6" | 2.9" | 💧 Light watering |
| Sep | 6.5" | 3.1" | 3.4" | 🚿 Regular watering |
| Oct | 6.5" | 2.4" | 4.1" | 🚿 Regular watering |
| Nov | — | 1.2" | 0" | ❄️ Dormant |
| Dec | — | 0.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Adair 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 — Adair County, OK
Watercress Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 3 | Mar 3 – Mar 17 |
| Transplant Outdoors | April 7 | Apr 7 – Apr 21 |
| Direct Sow | March 24 | Mar 24 – Apr 14 |
| Harvest | May 19 | May 19 – Jun 23 |
| Fall Sowing | August 18 | Aug 18 – Sep 1 |
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 · 2-3 times/week
📅 Days to Maturity
40–60 days
🧪 Soil pH
Needs 6.5–7.5 · Your soil: ideal
🗺️ USDA Zone
Zone 7b
📆 Growing Season
203 days in Adair County
Growing Tips for Watercress in Adair County
Direct sow Watercress outdoors after April 07 in Adair County when soil has warmed and frost danger has passed.
Your generous 203.0-day season in Adair 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 Adair County, OK?
Adair County is in Zone 7b with an average last frost of April 7. Plan your Watercress planting based on this frost date — see the calendar above for exact timing.
What planting zone is Adair County, OK?
Adair County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is April 7 and first fall frost is October 27.
Your Adair County Garden Planner — Free
A 24-page printable planner built for Adair 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.