When to Plant Foxglove in Castro County, TX
June to-do list for Castro County, Texas
A quick June briefing for Castro County, Texas gardeners — what's urgent, what's next, and what can wait.
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Time to start foxglove inside
Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.
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Start harvesting foxglove
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
Get ahead of July
- 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.
Castro County, Texas is in USDA Zone 7a. The average last spring frost is April 14 and the first fall frost is October 24, giving you a growing season of approximately 193 days.
At an elevation of 3,838 feet, Castro County receives approximately 47.6 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 95°F, so Foxglove may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Foxglove will need more frequent watering and organic matter to retain nutrients.
Castro County Soil Profile
Soil Type
Sandy Loam
Soil pH
7.5-8.1
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 Castro County
How your county's soil matches Foxglove's growing requirements.
Soil pH
Your soil pH (7.5–8.1) is more alkaline than Foxglove prefers (5.5–6.5). Add sulfur or peat moss to lower pH.
Soil Texture
Sandy soil in Castro County warms quickly in spring but drains fast. Foxglove will need more frequent watering and regular compost additions to retain nutrients.
Organic Matter
Organic matter is low (1.0%). Add 2-3 inches of compost before planting Foxglove.
How to Plant Foxglove
Succession Planting Foxglove
Sow every 9.1 weeks. Last sowing by Jun 26 to harvest before frost.
Foxglove Water Budget
Water stress score is 8/10 — 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 | — | 3.3" | 0" | ❄️ Dormant |
| Feb | — | 2.7" | 0" | ❄️ Dormant |
| Mar | — | 2.4" | 0" | ❄️ Dormant |
| Apr | 4.3" | 1.7" | 2.6" | 🚿 Regular watering |
| May | 4.3" | 1.2" | 3.1" | 🚿 Regular watering |
| Jun | 4.3" | 1.5" | 2.8" | 🚿 Regular watering |
| Jul | 4.3" | 8" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 8.9" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 6.8" | 0" | ✅ Rainfall sufficient |
| Oct | 4.3" | 4.9" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.5" | 0" | ❄️ Dormant |
| Dec | — | 3.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Castro 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 — Castro County, TX
Foxglove Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 17 | Feb 17 – Mar 3 |
| Transplant Outdoors | April 21 | Apr 21 – May 5 |
| Direct Sow | April 21 | Apr 21 – May 12 |
| Bloom | June 9 | Jun 9 – Jul 14 |
Plant 0.1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors |
| April | Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Bloom |
| July | Bloom |
| August | — |
| 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: too_alkaline
🗺️ USDA Zone
Zone 7a
📆 Growing Season
193 days in Castro County
Growing Tips for Foxglove in Castro County
Direct sow Foxglove outdoors after April 14 in Castro County when soil has warmed and frost danger has passed.
Sandy soil in Castro County dries quickly — mulch Foxglove with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
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 Castro County, TX?
Castro County is in Zone 7a with an average last frost of April 14. Plan your Foxglove planting based on this frost date — see the calendar above for exact timing.
What planting zone is Castro County, TX?
Castro County, Texas is in USDA Hardiness Zone 7a. The average last spring frost is April 14 and first fall frost is October 24.
Your Castro County Garden Planner — Free
A 22-page printable planner built for Castro County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.