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When to plant Hostas in Fillmore County County,

Plant Hostas in Fillmore County County, between May 17 and May 31 — the only viable window. Zone 4b's short season (156 frost-free days) rules out a fall crop.

When to Plant Hostas in Fillmore County, MN

Fillmore County, Minnesota Zone 4b June

This month in Fillmore County, Minnesota

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

Avg. last frost May 3
Avg. first frost October 6
Soil temp (4") 67°F
Watering Low
Pest pressure High
Daylight 15.2 hrs
Before July arrives, get these ready
  • Starting indoors: hostas

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Hostas (Hosta spp.) are the undisputed kings of the shade garden, grown primarily for their spectacular mounded foliage in shades of deep green, blue-green, gold, and variegated combinations. Originating in East Asia (Japan, China, Korea), hostas form dense, long-lived clumps that reliably return year after year with minimal care. In summer, tall scapes of lavender or white tubular flowers rise above the foliage — some cultivars (notably H. plantaginea hybrids) are notably fragrant. Extremely adaptable in moist, well-drained soil with consistent shade to part shade.

Fillmore County, Minnesota is in USDA Zone 4b. The average last spring frost is May 3 and the first fall frost is October 6, giving you a growing season of approximately 156 days.

At an elevation of 870 feet, Fillmore County receives approximately 37.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Hostas to ensure they mature before fall.

Perennial Blooms in Summer Pollinator-friendly
Fillmore County, MN (Zone 4b) Moderate season
156 days
Last Spring Frost May 3
156 growing days
First Fall Frost October 6
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Fillmore County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.3

Drainage

Well Drained

Hostas Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 9 Transplant: May 11 🌸 Bloom: Aug 10 – Oct 19
Recommended (50%) ✗ May not fit
Start indoors: Feb 15 Transplant: May 17 🌸 Bloom: Aug 16 – Oct 25
Safe Start (90%) ✗ May not fit
Start indoors: Feb 28 Transplant: May 30 🌸 Bloom: Aug 29 – Nov 7

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 Fillmore County

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

Soil pH

Your soil pH (6.0–7.3) is within Hostas's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.3%) — Hostas will thrive.

How to Plant Hostas

1"
Planting Depth
24"
Between Plants
30"
Between Rows

Succession Planting Hostas

3
successive plantings in your 156-day season

Sow every 6.9 weeks. Last sowing by Jul 08 to harvest before frost.

Hostas Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Hostas

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

Month Hostas Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 3.6" 0" ❄️ Dormant
May 4.3" 4" 0.3" 💧 Light watering
Jun 4.3" 5.1" 0" ✅ Rainfall sufficient
Jul 4.3" 3.8" 0.5" 💧 Light watering
Aug 4.3" 3.6" 0.7" 💧 Light watering
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 3" 1.3" 💧 Light watering
Nov 2.9" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

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

Hostas 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.

Hostas needs ~806 GDD — county provides 1,677 GDD Excellent fit

Hostas Planting Timeline — Fillmore County, MN

Hostas Planting Calendar

Activity When Date Range
Start Indoors February 15 Feb 15 – Mar 1
Transplant Outdoors May 17 May 17 – May 31
Bloom August 16 Aug 16 – Oct 25

Plant 1" deep · 24" apart · Rows 30" apart

Month-by-Month Timeline

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

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 4b

📆 Growing Season

156 days in Fillmore County

Growing Tips for Hostas in Fillmore County

Direct sow Hostas outdoors after May 03 in Fillmore County when soil has warmed and frost danger has passed.

General growing tips

Plant bare-root crowns or divisions in early spring just as new growth emerges, or in fall at least 6 weeks before hard freeze. Choose a site with morning sun and afternoon shade in Zones 6+; deeper shade is acceptable but reduces vigor and bloom. Keep consistently moist but never waterlogged. Apply a 2–3 inch mulch layer to conserve moisture and suppress weeds. Slugs are the primary pest — use iron phosphate bait if damage is significant. Deer will browse hostas heavily in most regions; protect with fencing or repellents. Divide every 3–5 years in spring to rejuvenate. Fall planting (Zones 4+) is equally effective as spring planting when soil stays workable. Year 2+ plants reach full size and flower most reliably; first-year divisions may produce limited flower spikes.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Hostas in Fillmore County, MN?

Fillmore County is in Zone 4b with an average last frost of May 3. Plan your Hostas planting based on this frost date — see the calendar above for exact timing.

What planting zone is Fillmore County, MN?

Fillmore County, Minnesota is in USDA Hardiness Zone 4b. The average last spring frost is May 3 and first fall frost is October 6.

When should I plant Hostas in Fillmore County County, ?

In Fillmore County County, , plant Hostas after the last frost (around May 3) and before the first frost (around October 6). Best results when soil holds above 50°F.

What growing zone is Fillmore County County, for Hostas?

Fillmore County County sits in USDA Zone 4b. Hostas grows reliably in zones 3a through 9a, so it's a good fit here.

Can Hostas grow in Fillmore County County's climate?

Yes — Hostas grows well in Fillmore County County's temperate climate. Fillmore County County averages a 156-day frost-free season, with last frost around May 3 and first frost around October 6.

🌱

Your Fillmore County Garden Planner — Free

A 22-page printable planner built for Fillmore 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 Fillmore County, MN. Local conditions may vary. Last updated: June 2026.

Sources & credits

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