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When to Plant Foxglove in Spokane County, WA

Spokane County, Washington Zone 6b June

Your June game plan for Spokane County, Washington

If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.

Avg. last frost May 11
Avg. first frost September 27
Soil temp (4") 70°F
Watering Critical
Pest pressure High
Daylight 15.8 hrs
July prep starts now
  • Starting indoors: foxglove
  • 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.

Spokane County, Washington is in USDA Zone 6b. The average last spring frost is May 11 and the first fall frost is September 27, giving you a growing season of approximately 139 days.

At an elevation of 1,645 feet, Spokane County receives approximately 20.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Foxglove during the growing season.

Perennial Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Spokane County, WA (Zone 6b) Short season
139 days
Last Spring Frost May 11
139 growing days
First Fall Frost September 27

Spokane County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.2

Drainage

Well Drained

Foxglove Planting Risk Windows

Early Start (70% safe) ✓ Fits season (43 days to spare)
Start indoors: Feb 26 Transplant: May 7 🌸 Bloom: Jul 2 – Aug 6
Recommended (50%) ✓ Fits season (41 days to spare)
Start indoors: Mar 9 Transplant: May 18 🌸 Bloom: Jul 13 – Aug 17
Safe Start (90%) ✓ Fits season (33 days to spare)
Start indoors: Apr 10 Transplant: Jun 19 🌸 Bloom: Aug 14 – Sep 18

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 Spokane County

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

Soil pH

Your soil pH (5.5–6.2) is within Foxglove's preferred range (5.5–6.5).

Soil Texture

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

Organic Matter

Organic matter is excellent (5.4%) — Foxglove will thrive.

How to Plant Foxglove

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

Foxglove Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 475 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 3.1" 0" ❄️ Dormant
Feb 2.2" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 1.7" 0" ❄️ Dormant
May 4.3" 1.3" 3" 🚿 Regular watering
Jun 4.3" 0.8" 3.5" 🚿 Regular watering
Jul 4.3" 0.3" 4" 🚿 Regular watering
Aug 4.3" 0.4" 3.9" 🚿 Regular watering
Sep 4.3" 0.7" 3.6" 🚿 Regular watering
Oct 1.5" 0" ❄️ Dormant
Nov 3.3" 0" ❄️ Dormant
Dec 3.2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Spokane 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 ~1,825 GDD — county provides 2,536 GDD Excellent fit

Foxglove Planting Timeline — Spokane County, WA

Foxglove Planting Calendar

Activity When Date Range
Start Indoors March 9 Mar 9 – Mar 23
Transplant Outdoors May 18 May 18 – Jun 1
Direct Sow May 18 May 18 – Jun 8
Bloom July 13 Jul 13 – Aug 17

Plant 0.1" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April
May Transplant Outdoors Direct Sow
June Transplant Outdoors Direct Sow
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: ideal

🗺️ USDA Zone

Zone 6b

📆 Growing Season

139 days in Spokane County

Growing Tips for Foxglove in Spokane County

Direct sow Foxglove outdoors after May 11 in Spokane County when soil has warmed and frost danger has passed.

Spokane County receives only 20" of rain annually. Foxglove needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Spokane County, WA?

Spokane County is in Zone 6b with an average last frost of May 11. Plan your Foxglove planting based on this frost date — see the calendar above for exact timing.

What planting zone is Spokane County, WA?

Spokane County, Washington is in USDA Hardiness Zone 6b. The average last spring frost is May 11 and first fall frost is September 27.

🌱

Your Spokane County Garden Planner — Free

A 22-page printable planner built for Spokane 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 Spokane County, WA. 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.