When to Plant Foxglove in Warren County, PA
Your June planting checklist for Warren County, Pennsylvania
Here's what deserves your attention in Warren County, Pennsylvania this month. Everything below is tailored to Zone 6a and timed around your local frost dates.
Get ahead of July
- Starting indoors: foxglove
- First harvests: foxglove
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.
Warren County, Pennsylvania is in USDA Zone 6a. The average last spring frost is May 13 and the first fall frost is October 13, giving you a growing season of approximately 153 days.
At an elevation of 1,158 feet, Warren County receives approximately 43.3 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.
Warren County Soil Profile
Soil Type
Silt Loam
Soil pH
5.1-6.2
Drainage
Well Drained
Foxglove Planting Risk Windows
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 Warren County
How your county's soil matches Foxglove's growing requirements.
Soil pH
Your soil pH (5.1–6.2) overlaps with Foxglove's range (5.5–6.5), though not a perfect match.
Soil Texture
The silt loam soil in Warren County is excellent for Foxglove — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.6%). Annual compost additions will help Foxglove.
How to Plant Foxglove
Succession Planting Foxglove
Sow every 9.1 weeks. Last sowing by Jun 15 to harvest before frost.
Foxglove Water Budget
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 | — | 3.3" | 0" | ❄️ Dormant |
| Feb | — | 2.8" | 0" | ❄️ Dormant |
| Mar | — | 3.6" | 0" | ❄️ Dormant |
| Apr | — | 3.4" | 0" | ❄️ Dormant |
| May | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Jun | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Jul | 4.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Sep | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Oct | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Nov | — | 3.7" | 0" | ❄️ Dormant |
| Dec | — | 2.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Warren 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 Planting Timeline — Warren County, PA
Foxglove Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 11 | Mar 11 – Mar 25 |
| Transplant Outdoors | May 20 | May 20 – Jun 3 |
| Direct Sow | May 20 | May 20 – Jun 10 |
| Bloom | July 15 | Jul 15 – Aug 19 |
Plant 0.1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| 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 · Natural rainfall sufficient
📅 Days to Maturity
80–120 days
🧪 Soil pH
Needs 5.5–6.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 6a
📆 Growing Season
153 days in Warren County
Growing Tips for Foxglove in Warren County
Direct sow Foxglove outdoors after May 13 in Warren 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 →
Foxglove in Other Locations
Frequently Asked Questions
When should I plant Foxglove in Warren County, PA?
Warren County is in Zone 6a with an average last frost of May 13. Plan your Foxglove planting based on this frost date — see the calendar above for exact timing.
What planting zone is Warren County, PA?
Warren County, Pennsylvania is in USDA Hardiness Zone 6a. The average last spring frost is May 13 and first fall frost is October 13.
Your Warren County Garden Planner — Free
A 22-page printable planner built for Warren County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.