When to Plant Foxglove in Custer County, OK
July in Custer County, Oklahoma — your action list
Your Custer County, Oklahoma garden is entering a new phase. Here's what's on the schedule for July and why each task matters now.
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Start harvesting foxglove
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
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.
Custer County, Oklahoma is in USDA Zone 7b. The average last spring frost is April 8 and the first fall frost is October 31, giving you a growing season of approximately 206 days.
At an elevation of 767 feet, Custer County receives approximately 31.6 inches of rainfall annually with predominantly loam soil. Summer highs average 89°F, providing good warmth for Foxglove during the growing season.
Custer County Soil Profile
Soil Type
Loam
Soil pH
6.5-7.2
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 Custer County
How your county's soil matches Foxglove's growing requirements.
Soil pH
Your soil pH (6.5–7.2) is more alkaline than Foxglove prefers (5.5–6.5). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Custer County is excellent for Foxglove — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.7%). Annual compost additions will help Foxglove.
How to Plant Foxglove
Succession Planting Foxglove
Sow every 9.1 weeks. Last sowing by Jul 03 to harvest before frost.
Foxglove Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
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 | — | 0.8" | 0" | ❄️ Dormant |
| Feb | — | 1.1" | 0" | ❄️ Dormant |
| Mar | — | 2.1" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| May | 4.3" | 4" | 0.3" | 💧 Light watering |
| Jun | 4.3" | 5.4" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Aug | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Sep | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| Oct | 4.3" | 1.9" | 2.4" | 🚿 Regular watering |
| Nov | — | 1.1" | 0" | ❄️ Dormant |
| Dec | — | 0.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Custer 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 — Custer County, OK
Foxglove Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 11 | Feb 11 – Feb 25 |
| Transplant Outdoors | April 15 | Apr 15 – Apr 29 |
| Direct Sow | April 15 | Apr 15 – May 6 |
| Bloom | June 3 | Jun 3 – Jul 8 |
Plant 0.1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | — |
| April | Transplant Outdoors Direct Sow |
| May | Direct Sow |
| June | Bloom |
| July | Bloom |
| August | — |
| 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: too_alkaline
🗺️ USDA Zone
Zone 7b
📆 Growing Season
206 days in Custer County
Growing Tips for Foxglove in Custer County
Direct sow Foxglove outdoors after April 08 in Custer 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 Custer County, OK?
Custer County is in Zone 7b with an average last frost of April 8. Plan your Foxglove planting based on this frost date — see the calendar above for exact timing.
What planting zone is Custer County, OK?
Custer County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is April 8 and first fall frost is October 31.
Your Custer County Garden Planner — Free
A 22-page printable planner built for Custer County (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.