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When to plant Geraniums in Watonwan County, MN

Watonwan County's 160-day season only supports one Geraniums planting per year. Sow between May 6 and May 20 for the best chance at full maturity before October 6.

When to Plant Geraniums in Watonwan County, MN

Watonwan County, Minnesota Zone 5a June

June to-do list for Watonwan County, Minnesota

Your garden in Watonwan County, Minnesota is working on a schedule, even when you're not. Here's where you should be this June.

Avg. last frost April 29
Avg. first frost October 6
Soil temp (4") 65°F
Watering Low
Pest pressure High
Daylight 15.3 hrs
Before July arrives, get these ready
  • Starting indoors: geraniums
  • 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.

Watonwan County, Minnesota is in USDA Zone 5a. The average last spring frost is April 29 and the first fall frost is October 6, giving you a growing season of approximately 160 days.

At an elevation of 984 feet, Watonwan County receives approximately 33.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 82°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
Watonwan County, MN (Zone 5a) Moderate season
160 days
Last Spring Frost April 29
160 growing days
First Fall Frost October 6

Watonwan County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-7.2

Drainage

Well Drained

Geraniums Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 13 Transplant: May 1 🌸 Bloom: Jul 10 – Oct 2
Recommended (50%) ✗ May not fit
Start indoors: Feb 18 Transplant: May 6 🌸 Bloom: Jul 15 – Oct 7
Safe Start (90%) ✗ May not fit
Start indoors: Mar 5 Transplant: May 21 🌸 Bloom: Jul 30 – Oct 22

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 Watonwan County

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

Soil pH

Your soil pH (5.8–7.2) overlaps with Geraniums's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.0%) — 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 160-day season

Sow every 8 weeks. Last sowing by Jun 28 to harvest before frost.

Geraniums Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 157 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 1.3" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 4.3" 3.3" 1" 💧 Light watering
May 4.3" 3.8" 0.5" 💧 Light watering
Jun 4.3" 4.4" 0" ✅ Rainfall sufficient
Jul 4.3" 3.7" 0.6" 💧 Light watering
Aug 4.3" 3.4" 0.9" 💧 Light watering
Sep 4.3" 3" 1.3" 💧 Light watering
Oct 4.3" 2.9" 1.4" 💧 Light watering
Nov 2.4" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Watonwan 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 ~978 GDD — county provides 1,840 GDD Excellent fit

Geraniums Planting Timeline — Watonwan County, MN

Geraniums Planting Calendar

Activity When Date Range
Start Indoors February 18 Feb 18 – Mar 4
Transplant Outdoors May 6 May 6 – May 20
Bloom July 15 Jul 15 – Oct 7

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
July Bloom
August Bloom
September Bloom
October Bloom
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

160 days in Watonwan County

Growing Tips for Geraniums in Watonwan County

Direct sow Geraniums outdoors after April 29 in Watonwan 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 Watonwan County, MN?

Watonwan County is in Zone 5a with an average last frost of April 29. Plan your Geraniums planting based on this frost date — see the calendar above for exact timing.

What planting zone is Watonwan County, MN?

Watonwan County, Minnesota is in USDA Hardiness Zone 5a. The average last spring frost is April 29 and first fall frost is October 6.

When should I plant Geraniums in Watonwan County, MN?

In Watonwan County, MN, plant Geraniums after the last frost (around April 29) and before the first frost (around October 6). Best results when soil holds above 50°F.

What growing zone is Watonwan County, MN for Geraniums?

Watonwan County sits in USDA Zone 5a. Geraniums grows reliably in zones 2a through 11b, so it's a good fit here.

Can Geraniums grow in Watonwan County's climate?

Yes — Geraniums grows well in Watonwan County's temperate climate. Watonwan County averages a 160-day frost-free season, with last frost around April 29 and first frost around October 6.

🌱

Your Watonwan County Garden Planner — Free

A 22-page printable planner built for Watonwan County (Zone 5a). 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 Watonwan County, MN. Local conditions may vary. Last updated: June 2026.

Sources & credits

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