When to plant Watermelon in Jefferson County, KS
Jefferson County's spring Watermelon window runs April 21 through May 12. time plantings around the expected last-frost window for best survival.
When to Plant Watermelon in Jefferson County, KS
Watermelon is a sprawling vine crop that produces sweet, juicy fruits in hot weather. Varieties range from personal-sized icebox types to 50-pound giants.
Jefferson County, Kansas is in USDA Zone 6b. The average last spring frost is April 14 and the first fall frost is October 24, giving you a growing season of approximately 193 days.
At an elevation of 559 feet, Jefferson County receives approximately 23.8 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Watermelon during the growing season.
Jefferson County Soil Profile
Soil Type
Loam
Soil pH
6.7-7.6
Drainage
Well Drained
How Much Watermelon to Grow
For a family of 4, plant approximately 4 watermelon plants in about 8 sq ft. In Jefferson County's 193-day season, you'll have plenty of time for a full harvest. Plan your garden layout →
Monthly Watering Guide for Watermelon
Watermelon needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Watermelon Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 0.7" | 0" | ❄️ Dormant |
| Feb | — | 0.7" | 0" | ❄️ Dormant |
| Mar | — | 1.4" | 0" | ❄️ Dormant |
| Apr | 4.3" | 2.5" | 1.8" | 💧 Light watering |
| May | 4.3" | 3.3" | 1" | 💧 Light watering |
| Jun | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Jul | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Aug | 4.3" | 2.6" | 1.7" | 💧 Light watering |
| Sep | 4.3" | 2.5" | 1.8" | 💧 Light watering |
| Oct | 4.3" | 1.4" | 2.9" | 🚿 Regular watering |
| Nov | — | 0.8" | 0" | ❄️ Dormant |
| Dec | — | 0.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Jefferson County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Watermelon Planting Timeline — Jefferson County, KS
Watermelon Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 10 | Mar 10 – Mar 24 |
| Transplant Outdoors | April 28 | Apr 28 – May 12 |
| Direct Sow | April 21 | Apr 21 – May 12 |
| Harvest | July 7 | Jul 7 – Aug 25 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Moderate — regular watering
📅 Days to Maturity
70–100 days
🧪 Soil pH
Needs 6–7.5 · Your soil: N/A
🗺️ USDA Zone
Zone 6b
📆 Growing Season
193 days in Jefferson County
Growing Tips for Jefferson County
Start seeds indoors 3-4 weeks early or direct sow after soil is warm. Plant on mounds with plenty of space. Check ripeness by looking for a yellow ground spot and dull thump when tapped.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Watermelon in Other Locations
Frequently Asked Questions
When should I plant Watermelon in Jefferson County, KS?
Jefferson County is in Zone 6b with an average last frost of April 14. Plan your Watermelon planting based on this frost date — see the calendar above for exact timing.
What planting zone is Jefferson County, KS?
Jefferson County, Kansas is in USDA Hardiness Zone 6b. The average last spring frost is April 14 and first fall frost is October 24.
When should I plant Watermelon in Jefferson County, KS?
In Jefferson County, KS, plant Watermelon after the last frost (around April 14) and before the first frost (around October 24). Best results when soil holds above 50°F.
What growing zone is Jefferson County, KS for Watermelon?
Jefferson County sits in USDA Zone 6b. Watermelon grows reliably in zones 4a through 11b, so it's a good fit here.
Can Watermelon grow in Jefferson County's climate?
Yes — Watermelon grows well in Jefferson County's temperate climate. Jefferson County averages a 193-day frost-free season, with last frost around April 14 and first frost around October 24.
Your Jefferson County Garden Planner — Free
A 22-page printable planner built for Jefferson County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.