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When to Plant Sweet Potatoes in Brown County, KS

Brown County, Kansas Zone 6a May

May in the garden — Brown County, Kansas

A quick May briefing for Brown County, Kansas gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 23
Avg. first frost October 11
Soil temp (4") 60°F
Watering Low
Pest pressure Low
Daylight 14.2 hrs
  1. Harden off and plant sweet potatoes

    Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.

To set up a strong June, finish these tasks
  • Starting indoors: sweet potatoes

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Sweet potatoes are a warm-season root crop that produces nutritious, sweet tubers in orange, white, and purple varieties. They need a long, hot growing season.

Brown County, Kansas is in USDA Zone 6a. The average last spring frost is April 23 and the first fall frost is October 11, giving you a growing season of approximately 171 days.

At an elevation of 485 feet, Brown County receives approximately 29.4 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Sweet Potatoes to ensure they mature before fall.

Brown County, KS (Zone 6a) Moderate season
171 days
Last Spring Frost April 23
171 growing days
First Fall Frost October 11
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Brown County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (18 days to spare)
Start indoors: Feb 20 Transplant: May 1 🍅 Harvest: Jul 31 – Sep 18
Recommended (50%) ✓ Fits season (17 days to spare)
Start indoors: Feb 26 Transplant: May 7 🍅 Harvest: Aug 6 – Sep 24
Safe Start (90%) ✓ Fits season (17 days to spare)
Start indoors: Mar 14 Transplant: May 23 🍅 Harvest: Aug 22 – Oct 10

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 Brown County

How your county's soil matches Sweet Potatoes's growing requirements.

Soil pH

Your soil pH (6.3–7.8) is more alkaline than Sweet Potatoes prefers (5.5–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Brown County is excellent for Sweet Potatoes — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Sweet Potatoes.

Organic Matter

Organic matter is moderate (3.7%). Annual compost additions will help Sweet Potatoes.

How to Plant Sweet Potatoes

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 1,055 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Sweet Potatoes

Sweet Potatoes needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Sweet Potatoes Needs Rainfall You Supplement Action
Jan 0.7" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 1.6" 0" ❄️ Dormant
Apr 4.3" 2.7" 1.6" 💧 Light watering
May 4.3" 4.7" 0" ✅ Rainfall sufficient
Jun 4.3" 5.2" 0" ✅ Rainfall sufficient
Jul 4.3" 3.9" 0.4" 💧 Light watering
Aug 4.3" 3.3" 1" 💧 Light watering
Sep 4.3" 2.7" 1.6" 💧 Light watering
Oct 4.3" 1.8" 2.5" 🚿 Regular watering
Nov 1.1" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Brown County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Sweet Potatoes 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.

Sweet Potatoes needs ~1,365 GDD — county provides 2,223 GDD Excellent fit

Sweet Potatoes Planting Timeline — Brown County, KS

Sweet Potatoes Planting Calendar

Activity When Date Range
Start Indoors February 26 Feb 26 – Mar 12
Transplant Outdoors May 7 May 7 – May 21
Direct Sow April 30 Apr 30 – May 21
Harvest August 6 Aug 6 – Sep 24

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors
April Direct Sow
May Transplant Outdoors Direct Sow
June
July
August Harvest
September Harvest
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 5.5–6.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6a

📆 Growing Season

171 days in Brown County

Growing Tips for Sweet Potatoes in Brown County

Direct sow Sweet Potatoes outdoors after April 23 in Brown County when soil has warmed and frost danger has passed.

General growing tips

Plant slips (rooted sprouts) after soil is thoroughly warm. Build raised mounds for better root development. Cure harvested roots at 80-85F for 10 days to develop sweetness.

Companion Planting

Good Companions

Avoid Planting Near

  • Squash Summer

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sweet Potatoes in Brown County, KS?

Brown County is in Zone 6a with an average last frost of April 23. Plan your Sweet Potatoes planting based on this frost date — see the calendar above for exact timing.

What planting zone is Brown County, KS?

Brown County, Kansas is in USDA Hardiness Zone 6a. The average last spring frost is April 23 and first fall frost is October 11.

🌱

Your Brown County Garden Planner — Free

A 24-page printable planner built for Brown 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.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Brown County, KS. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.