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When to plant Foxglove in Monroe County, MI

Aim to plant Foxglove in Monroe County on or after May 4; the window stays open through May 25. Monroe County's 173-day frost-free season gives you a single solid spring crop with a brief fall option.

When to Plant Foxglove in Monroe County, MI

Monroe County, Michigan Zone 6b July

Top priorities for Monroe County, Michigan gardeners in July

Your garden in Monroe County, Michigan is working on a schedule, even when you're not. Here's where you should be this July.

Avg. last frost April 27
Avg. first frost October 17
Soil temp (4") 79°F
Watering Low
Pest pressure High
Daylight 14.8 hrs
  1. Collect foxglove at their peak

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

August will be here before you know it — start on
  • First harvests: foxglove

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Foxglove (Digitalis purpurea) is a stately cottage garden classic, sending up dramatic 3–5 foot spires of tubular flowers — spotted purple, pink, white, or cream — in late spring and early summer. Technically biennial (flowering in its second year), foxglove perpetuates itself so freely from self-sown seed that established plantings appear to be permanent perennials. A key source plant for the heart medication digitalis, all parts are highly toxic if ingested. Bumblebees are the primary pollinators, crawling deep into each bell-shaped flower. Partial shade and cool, moist woodland-edge conditions suit foxglove best; it resents heat and drought.

Monroe County, Michigan is in USDA Zone 6b. The average last spring frost is April 27 and the first fall frost is October 17, giving you a growing season of approximately 173 days.

At an elevation of 1,202 feet, Monroe County receives approximately 40.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Foxglove during the growing season.

Perennial Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Monroe County, MI (Zone 6b) Moderate season
173 days
Last Spring Frost April 27
173 growing days
First Fall Frost October 17

Monroe County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-7.2

Drainage

Well Drained

Foxglove Planting Risk Windows

Early Start (70% safe) ✓ Fits season (71 days to spare)
Start indoors: Feb 20 Transplant: May 1 🌸 Bloom: Jun 26 – Jul 31
Recommended (50%) ✓ Fits season (75 days to spare)
Start indoors: Feb 23 Transplant: May 4 🌸 Bloom: Jun 29 – Aug 3
Safe Start (90%) ✓ Fits season (72 days to spare)
Start indoors: Mar 11 Transplant: May 20 🌸 Bloom: Jul 15 – Aug 19

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 Monroe County

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

Soil pH

Your soil pH (5.8–7.2) overlaps with Foxglove's range (5.5–6.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Foxglove.

Organic Matter

Organic matter is excellent (4.2%) — Foxglove will thrive.

How to Plant Foxglove

0.1"
Planting Depth
18"
Between Plants
24"
Between Rows

Succession Planting Foxglove

2
successive plantings in your 173-day season

Sow every 9.1 weeks. Last sowing by Jun 19 to harvest before frost.

Foxglove Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 484 gal / 100 sq ft

Monthly Watering Guide for Foxglove

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

Month Foxglove Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 3.1" 0" ❄️ Dormant
Apr 4.3" 3.5" 0.8" 💧 Light watering
May 4.3" 4.7" 0" ✅ Rainfall sufficient
Jun 4.3" 5.6" 0" ✅ Rainfall sufficient
Jul 4.3" 4.3" 0" ✅ Rainfall sufficient
Aug 4.3" 4.5" 0" ✅ Rainfall sufficient
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 3.5" 0.8" 💧 Light watering
Nov 2.6" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

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

Foxglove 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.

Foxglove needs ~1,675 GDD — county provides 2,897 GDD Excellent fit

Foxglove Planting Timeline — Monroe County, MI

Foxglove Planting Calendar

Activity When Date Range
Start Indoors February 23 Feb 23 – Mar 9
Transplant Outdoors May 4 May 4 – May 18
Direct Sow May 4 May 4 – May 25
Bloom June 29 Jun 29 – Aug 3

Plant 0.1" 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 Bloom
July Bloom
August Bloom
September
October
November
December

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

80–120 days

🧪 Soil pH

Needs 5.5–6.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

173 days in Monroe County

Growing Tips for Foxglove in Monroe County

Direct sow Foxglove outdoors after April 27 in Monroe County when soil has warmed and frost danger has passed.

General growing tips

Sow seeds indoors 8–10 weeks before last frost or direct-sow outdoors in late spring/early summer for next-year bloom (biennial cycle). Surface-sow — seeds need light to germinate. Transplant after last frost into cool, moist, well-amended soil. Morning sun with afternoon shade is ideal; full shade reduces bloom but is tolerated. Keep consistently moist. First-year plants form a basal rosette only; second-year plants produce flower spikes. After bloom, cut the main spike before seed scatters to prevent excessive spreading, or leave some spikes to self-seed for naturalizing. Perennial species (D. grandiflora, D. x mertonensis) maintain clumps without requiring self-seeding. Wear gloves when handling — all plant parts toxic.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Foxglove in Monroe County, MI?

Monroe County is in Zone 6b with an average last frost of April 27. Plan your Foxglove planting based on this frost date — see the calendar above for exact timing.

What planting zone is Monroe County, MI?

Monroe County, Michigan is in USDA Hardiness Zone 6b. The average last spring frost is April 27 and first fall frost is October 17.

When should I plant Foxglove in Monroe County, MI?

In Monroe County, MI, plant Foxglove after the last frost (around April 27) and before the first frost (around October 17). Best results when soil holds above 50°F.

What growing zone is Monroe County, MI for Foxglove?

Monroe County sits in USDA Zone 6b. Foxglove grows reliably in zones 3a through 9a, so it's a good fit here.

Can Foxglove grow in Monroe County's climate?

Yes — Foxglove grows well in Monroe County's temperate climate. Monroe County averages a 173-day frost-free season, with last frost around April 27 and first frost around October 17.

🌱

Your Monroe County Garden Planner — Free

A 22-page printable planner built for Monroe County (Zone 6b). 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 Monroe County, MI. 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.