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When to Plant Elderberries in Marathon County, WI

Elderberries are fast-growing shrubs or small trees producing clusters of small, dark berries used for syrups, wines, and immune-boosting preparations. The flowers are also edible.

Marathon County, Wisconsin is in USDA Zone 4a. The average last spring frost is May 11 and the first fall frost is October 2, giving you a growing season of approximately 144 days.

At an elevation of 723 feet, Marathon County receives approximately 39.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Elderberries to ensure they mature before fall.

Marathon County, WI (Zone 4a) Short season
144 days
Last Spring Frost May 11
144 growing days
First Fall Frost October 2

Marathon County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: May 31
Recommended (50%) ✓ Fits season
Transplant: Jun 8
Safe Start (90%) ✓ Fits season
Transplant: Jun 18

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Elderberries needs ~11,178 GDD — county provides 1,764 GDD May not mature

Elderberries Planting Timeline โ€” Marathon County, WI

Elderberries Planting Calendar

Activity When Date Range
Transplant Outdoors June 8 Jun 8 โ€“ Jun 22

ยท 120" apart ยท Rows 144" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

730โ€“1095 days

Soil pH

5.5 โ€“ 6.5

USDA Zone

Zone 4a

Growing Season

144 days

Growing Tips for Marathon County

Plant at least two varieties for cross-pollination. Prune annually to remove old canes and maintain shape. Berries must be cooked before eating as raw berries are mildly toxic.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Elderberries in Marathon County, WI?

Marathon County is in Zone 4a with an average last frost of May 11. Plan your Elderberries planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Marathon County, WI?

Marathon County, Wisconsin is in USDA Hardiness Zone 4a. The average last spring frost is May 11 and first fall frost is October 2.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Marathon County gardeners in Zone 4a organize planting dates, track what's growing, and never miss a planting window.

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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 Marathon County, WI. Local conditions may vary. Last updated: April 2026.