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When to plant Phlox in Winona County, MN

Winona County gardeners should plant Phlox between May 14 and June 4 in spring. With Winona County's Zone 4b climate (last frost April 30), Phlox needs 80–110 days to mature — plant by June 19 for a full harvest.

When to Plant Phlox in Winona County, MN

Garden Phlox (Phlox paniculata) is a beloved native perennial of eastern North America, producing large, domed clusters of fragrant flowers atop upright stems from mid-summer into fall. Its sweet honey-like fragrance carries on summer evenings and draws hummingbirds, butterflies, and sphinx moths. Modern cultivars offer colors spanning white, pink, salmon, red, purple, and bicolors. A classic cottage garden stalwart, phlox combines well with black-eyed Susans, echinacea, and ornamental grasses in naturalistic plantings. Select mildew-resistant cultivars for best long-term performance.

Winona County, Minnesota is in USDA Zone 4b. The average last spring frost is April 30 and the first fall frost is October 7, giving you a growing season of approximately 160 days.

At an elevation of 1,396 feet, Winona County receives approximately 37.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Phlox to ensure they mature before fall.

Perennial Blooms in Summer Pollinator-friendly Good for cutting Fragrant
Winona County, MN (Zone 4b) Moderate season
160 days
Last Spring Frost April 30
160 growing days
First Fall Frost October 7

Winona County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-6.8

Drainage

Well Drained

Monthly Watering Guide for Phlox

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

Month Phlox Needs Rainfall You Supplement Action
Jan 1.7" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 4.3" 3.9" 0.4" 💧 Light watering
May 4.3" 4.5" 0" ✅ Rainfall sufficient
Jun 4.3" 4.2" 0.1" 💧 Light watering
Jul 4.3" 4.3" 0" ✅ Rainfall sufficient
Aug 4.3" 4.1" 0.2" 💧 Light watering
Sep 4.3" 2.8" 1.5" 💧 Light watering
Oct 4.3" 3.2" 1.1" 💧 Light watering
Nov 2.6" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

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

Phlox Planting Timeline — Winona County, MN

Phlox Planting Calendar

Activity When Date Range
Start Indoors February 19 Feb 19 – Mar 5
Transplant Outdoors May 14 May 14 – May 28
Direct Sow May 14 May 14 – Jun 4
Bloom August 6 Aug 6 – Oct 15

Plant 0.3" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

80–110 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 4b

📆 Growing Season

160 days in Winona County

Growing Tips for Winona County

Start seeds indoors 8–10 weeks before last frost, or transplant container divisions in spring. Named cultivar seeds may not come true; divisions from named plants are the preferred propagation method. Space generously (18–24 inches) and avoid overhead watering to reduce powdery mildew risk. Good air circulation is critical — thin clumps to the strongest 5–7 stems per plant in spring. Deadhead after the primary bloom flush to encourage secondary flowering. Division every 2–3 years in spring keeps plants vigorous. Fall planting of divisions (Zones 5+) is equally effective. Year 2+ plants develop into full clumps with the most prolific bloom.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Phlox in Winona County, MN?

Winona County is in Zone 4b with an average last frost of April 30. Plan your Phlox planting based on this frost date — see the calendar above for exact timing.

What planting zone is Winona County, MN?

Winona County, Minnesota is in USDA Hardiness Zone 4b. The average last spring frost is April 30 and first fall frost is October 7.

When should I plant Phlox in Winona County, MN?

In Winona County, MN, plant Phlox after the last frost (around April 30) and before the first frost (around October 7). Best results when soil holds above 50°F.

What growing zone is Winona County, MN for Phlox?

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

Can Phlox grow in Winona County's climate?

Yes — Phlox grows well in Winona County's temperate climate. Winona County averages a 160-day frost-free season, with last frost around April 30 and first frost around October 7.

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Your Winona County Garden Planner — Free

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

Sources & credits

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