When to Plant Mulberries in Polk County, WI
Your May game plan for Polk County, Wisconsin
Your Polk County, Wisconsin garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.
Before June arrives, get these ready
- Transplants going out: mulberries
Mulberries are fast-growing, long-lived trees that produce abundant sweet-tart berries over an extended harvest period. The berries resemble elongated blackberries.
Polk County, Wisconsin is in USDA Zone 4b. The average last spring frost is May 12 and the first fall frost is September 29, giving you a growing season of approximately 140 days.
At an elevation of 582 feet, Polk County receives approximately 40 inches of rainfall annually with predominantly silt loam soil. Summer highs average 82°F, so choose short-season varieties of Mulberries to ensure they mature before fall.
Polk County Soil Profile
Soil Type
Silt Loam
Soil pH
6-6.9
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 Polk County
How your county's soil matches Mulberries's growing requirements.
Soil pH
Your soil pH (6.0–6.9) is within Mulberries's preferred range (5.5–7.0).
Soil Texture
The silt loam soil in Polk County is excellent for Mulberries — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.9%). Annual compost additions will help Mulberries.
How to Plant Mulberries
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
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 | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 2" | 0" | ❄️ Dormant |
| Mar | — | 2.8" | 0" | ❄️ Dormant |
| Apr | — | 3.8" | 0" | ❄️ Dormant |
| May | 4.3" | 4.7" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 5.3" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.6" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Sep | 4.3" | 3.3" | 1" | 💧 Light watering |
| Oct | — | 2.8" | 0" | ❄️ Dormant |
| Nov | — | 2.6" | 0" | ❄️ Dormant |
| Dec | — | 2.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Polk 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 Planting Timeline — Polk County, WI
Mulberries Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | June 9 | Jun 9 – Jun 23 |
· 120" apart · Rows 144" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | — |
| June | Transplant Outdoors |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Natural rainfall sufficient
📅 Days to Maturity
730–1825 days
🧪 Soil pH
Needs 5.5–7 · Your soil: ideal
🗺️ USDA Zone
Zone 4b
📆 Growing Season
140 days in Polk County
Growing Tips for Mulberries in Polk County
Direct sow Mulberries outdoors after May 12 in Polk County when soil has warmed and frost danger has passed.
Your 140.0-day growing season in Polk County is tight for Mulberries (730.0-1825.0 days to maturity). Start indoors and choose early-maturing varieties.
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 →
Mulberries in Other Locations
Frequently Asked Questions
When should I plant Mulberries in Polk County, WI?
Polk County is in Zone 4b with an average last frost of May 12. Plan your Mulberries planting based on this frost date — see the calendar above for exact timing.
What planting zone is Polk County, WI?
Polk County, Wisconsin is in USDA Hardiness Zone 4b. The average last spring frost is May 12 and first fall frost is September 29.
Your Polk County Garden Planner — Free
A 24-page printable planner built for Polk 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.