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When to Plant Wax Beans in Roberts County, SD

Roberts County, South Dakota Zone 4b May

Top priorities for Roberts County, South Dakota gardeners in May

We've pulled the most time-sensitive tasks for Roberts County, South Dakota this May and put them front and centre. Tackle them in order.

Avg. last frost May 2
Avg. first frost October 6
Soil temp (4") 55°F
Watering Moderate
Pest pressure Low
Daylight 14.7 hrs
  1. Seed wax beans outdoors

    Rake a smooth bed, make a shallow furrow, drop seeds at the spacing on the packet, water gently, walk away.

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Wax beans are a yellow-podded variety of snap beans with a buttery, slightly sweeter flavor than green beans. They are easy to spot on the plant for picking.

Roberts County, South Dakota is in USDA Zone 4b. The average last spring frost is May 2 and the first fall frost is October 6, giving you a growing season of approximately 157 days.

At an elevation of 961 feet, Roberts County receives approximately 23.3 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Wax Beans to ensure they mature before fall.

Roberts County, SD (Zone 4b) Moderate season
157 days
Last Spring Frost May 2
157 growing days
First Fall Frost October 6

Roberts County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (48 days to spare)
Transplant: Apr 25 🍅 Harvest: Jun 20 – Aug 15
Recommended (50%) ✓ Fits season (45 days to spare)
Transplant: May 2 🍅 Harvest: Jun 27 – Aug 22
Safe Start (90%) ✓ Fits season (42 days to spare)
Transplant: May 16 🍅 Harvest: Jul 11 – Sep 5

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 Roberts County

How your county's soil matches Wax Beans's growing requirements.

Soil pH

Your soil pH (6.7–7.2) overlaps with Wax Beans's range (6.0–7.0), though not a perfect match.

Soil Texture

The loam soil in Roberts County is excellent for Wax Beans — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.8%). Annual compost additions will help Wax Beans.

How to Plant Wax Beans

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

Succession Planting Wax Beans

3
successive plantings in your 157-day season

Sow every 5.7 weeks. Last sowing by Aug 02 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 526 gal / 100 sq ft

Monthly Watering Guide for Wax Beans

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

Month Wax Beans Needs Rainfall You Supplement Action
Jan 0.6" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.4" 0" ❄️ Dormant
Apr 2.6" 0" ❄️ Dormant
May 4.3" 3.5" 0.8" 💧 Light watering
Jun 4.3" 4.1" 0.2" 💧 Light watering
Jul 4.3" 3.2" 1.1" 💧 Light watering
Aug 4.3" 2.4" 1.9" 💧 Light watering
Sep 4.3" 1.9" 2.4" 🚿 Regular watering
Oct 4.3" 1.4" 2.9" 🚿 Regular watering
Nov 0.8" 0" ❄️ Dormant
Dec 0.6" 0" ❄️ Dormant

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

Wax Beans 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.

Wax Beans needs ~575 GDD — county provides 1,570 GDD Excellent fit

Wax Beans Planting Timeline — Roberts County, SD

Wax Beans Planting Calendar

Activity When Date Range
Direct Sow May 16 May 16 – Jun 6
Harvest July 11 Jul 11 – Sep 5

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

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Direct Sow
June Direct Sow
July Harvest
August Harvest
September Harvest
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

50–65 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 4b

📆 Growing Season

157 days in Roberts County

Growing Tips for Wax Beans in Roberts County

Direct sow Wax Beans outdoors after May 02 in Roberts County when soil has warmed and frost danger has passed.

Common pests for Wax Beans in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.

Roberts County receives only 23" of rain annually. Wax Beans needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow after last frost. Pick pods regularly when young and tender. Bush types produce a concentrated harvest while pole types yield longer. Avoid working around wet plants.

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Wax Beans in Roberts County, SD?

Roberts County is in Zone 4b with an average last frost of May 2. Plan your Wax Beans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Roberts County, SD?

Roberts County, South Dakota is in USDA Hardiness Zone 4b. The average last spring frost is May 2 and first fall frost is October 6.

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Your Roberts County Garden Planner — Free

A 24-page printable planner built for Roberts County (Zone 4b). 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 Roberts County, SD. 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.