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When to Plant Geraniums in Burnett County, WI

Burnett County, Wisconsin Zone 4a July

This month in Burnett County, Wisconsin

Your Burnett County, Wisconsin garden is entering a new phase. Here's what's on the schedule for July and why each task matters now.

Avg. last frost May 15
Avg. first frost September 27
Soil temp (4") 67°F
Watering Moderate
Pest pressure Moderate
Daylight 15.2 hrs
  1. Sow geraniums in trays indoors

    These need a head start before your last frost (May 15). Sow into cells now so you're ready to transplant in a few weeks.

A few tasks this July that'll pay off in August
  • First harvests: geraniums

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Geraniums (Pelargonium × hortorum) are tender perennials grown as warm-season annuals throughout North America. Prized for their bold flower clusters, long bloom period, and tolerance of summer heat when planted in well-drained soil, they anchor window boxes, containers, and bed borders from late spring until hard frost. Zones 9b–11b can overwinter plants in the ground.

Burnett County, Wisconsin is in USDA Zone 4a. The average last spring frost is May 15 and the first fall frost is September 27, giving you a growing season of approximately 135 days.

At an elevation of 574 feet, Burnett County receives approximately 30.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 79°F, so choose short-season varieties of Geraniums to ensure they mature before fall.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Burnett County, WI (Zone 4a) Short season
135 days
Last Spring Frost May 15
135 growing days
First Fall Frost September 27

Burnett County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.3

Drainage

Well Drained

Geraniums Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 21 Transplant: May 23 🌸 Bloom: Aug 1 – Oct 3
Recommended (50%) ✗ May not fit
Start indoors: Feb 27 Transplant: May 29 🌸 Bloom: Aug 7 – Oct 9
Safe Start (90%) ✗ May not fit
Start indoors: Mar 14 Transplant: Jun 13 🌸 Bloom: Aug 22 – Oct 24

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 Burnett County

How your county's soil matches Geraniums's growing requirements.

Soil pH

Your soil pH (6.2–7.3) overlaps with Geraniums's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Burnett County is excellent for Geraniums — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Geraniums.

Organic Matter

Organic matter is excellent (4.6%) — Geraniums will thrive.

How to Plant Geraniums

0.1"
Planting Depth
12"
Between Plants
14"
Between Rows

Succession Planting Geraniums

2
successive plantings in your 135-day season

Sow every 8 weeks. Last sowing by Jun 19 to harvest before frost.

Geraniums Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 422 gal / 100 sq ft

Monthly Watering Guide for Geraniums

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

Month Geraniums Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 1.8" 0" ❄️ Dormant
Apr 2.6" 0" ❄️ Dormant
May 4.3" 3.6" 0.7" 💧 Light watering
Jun 4.3" 4.2" 0.1" 💧 Light watering
Jul 4.3" 3" 1.3" 💧 Light watering
Aug 4.3" 3.6" 0.7" 💧 Light watering
Sep 4.3" 2.7" 1.6" 💧 Light watering
Oct 2.5" 0" ❄️ Dormant
Nov 2" 0" ❄️ Dormant
Dec 1.7" 0" ❄️ Dormant

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

Geraniums 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.

Geraniums needs ~786 GDD — county provides 1,248 GDD Excellent fit

Geraniums Planting Timeline — Burnett County, WI

Geraniums Planting Calendar

Activity When Date Range
Start Indoors February 27 Feb 27 – Mar 13
Transplant Outdoors May 29 May 29 – Jun 12
Bloom August 7 Aug 7 – Oct 9

Plant 0.1" deep · 12" apart · Rows 14" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 4a

📆 Growing Season

135 days in Burnett County

Growing Tips for Geraniums in Burnett County

Direct sow Geraniums outdoors after May 15 in Burnett County when soil has warmed and frost danger has passed.

General growing tips

Start seeds indoors 10–12 weeks before last frost — germination is slow and erratic without bottom heat (70–75°F). Transplant after frost danger passes. Geraniums rarely direct-sown; cuttings or transplants are the standard. Deadhead spent umbels weekly to maintain continuous bloom. Let soil dry slightly between waterings to prevent root rot. In zones 10–11 plants may be left in ground year-round or overwintered as houseplants.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Geraniums in Burnett County, WI?

Burnett County is in Zone 4a with an average last frost of May 15. Plan your Geraniums planting based on this frost date — see the calendar above for exact timing.

What planting zone is Burnett County, WI?

Burnett County, Wisconsin is in USDA Hardiness Zone 4a. The average last spring frost is May 15 and first fall frost is September 27.

🌱

Your Burnett County Garden Planner — Free

A 22-page printable planner built for Burnett County (Zone 4a). 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 Burnett County, WI. Local conditions may vary. Last updated: July 2026.

Sources & credits

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