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When to plant Foxglove in Winnebago County County,

Winnebago County County gardeners should plant Foxglove between May 12 and June 2 in spring. With Winnebago County County's Zone 5a climate (last frost April 28), Foxglove needs 120 days to mature — plant by June 8 for a full harvest.

When to Plant Foxglove in Winnebago County, IA

Winnebago County, Iowa Zone 5a June

June in the garden — Winnebago County, Iowa

We've pulled the most time-sensitive tasks for Winnebago County, Iowa this June and put them front and centre. Tackle them in order.

Avg. last frost April 28
Avg. first frost October 6
Soil temp (4") 65°F
Watering Low
Pest pressure High
Daylight 15.2 hrs
  1. Start foxglove indoors

    These need a head start before your last frost (April 28). Sow into cells now so you're ready to transplant in a few weeks.

Get ahead of July
  • 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.

Winnebago County, Iowa is in USDA Zone 5a. The average last spring frost is April 28 and the first fall frost is October 6, giving you a growing season of approximately 161 days.

At an elevation of 520 feet, Winnebago County receives approximately 32.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Foxglove to ensure they mature before fall.

Perennial Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Winnebago County, IA (Zone 5a) Moderate season
161 days
Last Spring Frost April 28
161 growing days
First Fall Frost October 6
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Winnebago County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.9

Drainage

Well Drained

Foxglove Planting Risk Windows

Early Start (70% safe) ✓ Fits season (51 days to spare)
Start indoors: Feb 18 Transplant: May 6 🌸 Bloom: Jul 1 – Aug 12
Recommended (50%) ✓ Fits season (49 days to spare)
Start indoors: Feb 24 Transplant: May 12 🌸 Bloom: Jul 7 – Aug 18
Safe Start (90%) ✓ Fits season (47 days to spare)
Start indoors: Mar 8 Transplant: May 24 🌸 Bloom: Jul 19 – Aug 30

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 Winnebago County

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

Soil pH

Your soil pH (6.0–6.9) overlaps with Foxglove's range (5.5–6.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.1%) — 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 161-day season

Sow every 9.1 weeks. Last sowing by Jun 08 to harvest before frost.

Foxglove Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 226 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 1.3" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 4.3" 3" 1.3" 💧 Light watering
May 4.3" 3.2" 1.1" 💧 Light watering
Jun 4.3" 4" 0.3" 💧 Light watering
Jul 4.3" 3.9" 0.4" 💧 Light watering
Aug 4.3" 3.4" 0.9" 💧 Light watering
Sep 4.3" 2.8" 1.5" 💧 Light watering
Oct 4.3" 2.8" 1.5" 💧 Light watering
Nov 2.4" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Winnebago 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 ~1,300 GDD — county provides 2,093 GDD Excellent fit

Foxglove Planting Timeline — Winnebago County, IA

Foxglove Planting Calendar

Activity When Date Range
Start Indoors February 24 Feb 24 – Mar 10
Transplant Outdoors May 12 May 12 – May 26
Direct Sow May 12 May 12 – Jun 2
Bloom July 7 Jul 7 – Aug 18

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 Direct Sow
July Bloom
August Bloom
September
October
November
December
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Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

80–120 days

🧪 Soil pH

Needs 5.5–6.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

161 days in Winnebago County

Growing Tips for Foxglove in Winnebago County

Direct sow Foxglove outdoors after April 28 in Winnebago 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 Winnebago County, IA?

Winnebago County is in Zone 5a with an average last frost of April 28. Plan your Foxglove planting based on this frost date — see the calendar above for exact timing.

What planting zone is Winnebago County, IA?

Winnebago County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 28 and first fall frost is October 6.

When should I plant Foxglove in Winnebago County County, ?

In Winnebago County County, , plant Foxglove after the last frost (around April 28) and before the first frost (around October 6). Best results when soil holds above 50°F.

What growing zone is Winnebago County County, for Foxglove?

Winnebago County County sits in USDA Zone 5a. Foxglove grows reliably in zones 3a through 9a, so it's a good fit here.

Can Foxglove grow in Winnebago County County's climate?

Yes — Foxglove grows well in Winnebago County County's temperate climate. Winnebago County County averages a 161-day frost-free season, with last frost around April 28 and first frost around October 6.

🌱

Your Winnebago County Garden Planner — Free

A 22-page printable planner built for Winnebago 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 Winnebago County, IA. 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.