When to plant Foxglove in Johnson County, AR
In Johnson County, plant Foxglove in spring between March 26 and April 16, once soil temps hold above 50°F. Johnson County's last frost averages March 26, so most warm-season crops establish quickly once soil holds above 60°F. For a fall crop, sow between and — roughly 120 days before the first frost on November 3.
When to Plant Foxglove in Johnson County, AR
Your June game plan for Johnson County, Arkansas
Your garden in Johnson County, Arkansas is working on a schedule, even when you're not. Here's where you should be this June.
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Start harvesting foxglove
Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.
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.
Johnson County, Arkansas is in USDA Zone 8a. The average last spring frost is March 26 and the first fall frost is November 3, giving you a growing season of approximately 222 days.
At an elevation of 1,347 feet, Johnson County receives approximately 49.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Foxglove during the growing season.
Johnson County Soil Profile
Soil Type
Silt Loam
Soil pH
5.3-7
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 Johnson County
How your county's soil matches Foxglove's growing requirements.
Soil pH
Your soil pH (5.3–7.0) overlaps with Foxglove's range (5.5–6.5), though not a perfect match.
Soil Texture
The silt loam soil in Johnson County is excellent for Foxglove — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.6%). Annual compost additions will help Foxglove.
How to Plant Foxglove
Succession Planting Foxglove
Sow every 9.1 weeks. Last sowing by Jul 06 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 | — | 3.8" | 0" | ❄️ Dormant |
| Feb | — | 3.8" | 0" | ❄️ Dormant |
| Mar | 4.3" | 4.7" | 0" | ✅ Rainfall sufficient |
| Apr | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| May | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Jun | 4.3" | 5" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.6" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Oct | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Nov | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Dec | — | 3.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Johnson 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 — Johnson County, AR
Foxglove Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 29 | Jan 29 – Feb 12 |
| Transplant Outdoors | March 26 | Mar 26 – Apr 9 |
| Direct Sow | March 26 | Mar 26 – Apr 16 |
| Bloom | May 14 | May 14 – Jun 11 |
Plant 0.1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Start Indoors |
| March | Transplant Outdoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | Bloom |
| June | Bloom |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
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 8a
📆 Growing Season
222 days in Johnson County
Growing Tips for Foxglove in Johnson County
Direct sow Foxglove outdoors after March 26 in Johnson 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 Johnson County, AR?
Johnson County is in Zone 8a with an average last frost of March 26. Plan your Foxglove planting based on this frost date — see the calendar above for exact timing.
What planting zone is Johnson County, AR?
Johnson County, Arkansas is in USDA Hardiness Zone 8a. The average last spring frost is March 26 and first fall frost is November 3.
When should I plant Foxglove in Johnson County, AR?
In Johnson County, AR, plant Foxglove after the last frost (around March 26) and before the first frost (around November 3). Best results when soil holds above 50°F.
What growing zone is Johnson County, AR for Foxglove?
Johnson County sits in USDA Zone 8a. Foxglove grows reliably in zones 3a through 9a, so it's a good fit here.
Can Foxglove grow in Johnson County's climate?
Yes — Foxglove grows well in Johnson County's temperate climate. Johnson County averages a 222-day frost-free season, with last frost around March 26 and first frost around November 3.
Your Johnson County Garden Planner — Free
A 22-page printable planner built for Johnson County (Zone 8a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.