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When to Plant Mulberries in Roberts County, SD

Roberts County, South Dakota Zone 4b May

Top priorities for Roberts County, South Dakota gardeners in May

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Roberts County, South Dakota.

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. Harden off and plant mulberries

    Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.

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Mulberries are fast-growing, long-lived trees that produce abundant sweet-tart berries over an extended harvest period. The berries resemble elongated blackberries.

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 Mulberries 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
Transplant: May 23
Recommended (50%) ✓ Fits season
Transplant: May 30
Safe Start (90%) ✓ Fits season
Transplant: Jun 13

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 Mulberries's growing requirements.

Soil pH

Your soil pH (6.7–7.2) overlaps with Mulberries's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

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

How to Plant Mulberries

120"
Between Plants
144"
Between Rows

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 Mulberries

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

Month Mulberries 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.

Mulberries 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.

Mulberries needs ~12,775 GDD — county provides 1,570 GDD May not mature

Mulberries Planting Timeline — Roberts County, SD

Mulberries Planting Calendar

Activity When Date Range
Transplant Outdoors May 30 May 30 – Jun 13

· 120" apart · Rows 144" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Transplant Outdoors
June Transplant Outdoors
July
August
September
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

730–1825 days

🧪 Soil pH

Needs 5.5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 4b

📆 Growing Season

157 days in Roberts County

Growing Tips for Mulberries in Roberts County

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

Your 157.0-day growing season in Roberts County is tight for Mulberries (730.0-1825.0 days to maturity). Start indoors and choose early-maturing varieties.

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

General growing tips

Plant away from driveways and patios as fallen berries stain. Minimal pruning is needed. Harvest by shaking branches over a tarp. Birds love mulberries so plant extra.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Mulberries in Roberts County, SD?

Roberts County is in Zone 4b with an average last frost of May 2. Plan your Mulberries 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.

🌱

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.