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When to Plant Foxglove in Cass County, TX

Cass County, Texas Zone 8b June

Your June planting checklist for Cass County, Texas

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Cass County, Texas.

Avg. last frost March 14
Avg. first frost November 16
Soil temp (4") 84°F
Watering Low
Pest pressure High
Daylight 14.2 hrs

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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.

Cass County, Texas is in USDA Zone 8b. The average last spring frost is March 14 and the first fall frost is November 16, giving you a growing season of approximately 247 days.

At an elevation of 392 feet, Cass County receives approximately 71.7 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 94°F, providing good warmth for Foxglove during the growing season. Sandy soil warms quickly in spring — great for early planting — but Foxglove will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Foxglove root diseases.

Perennial Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Cass County, TX (Zone 8b) Long season
247 days
Last Spring Frost March 14
247 growing days
First Fall Frost November 16
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Cass County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.6-6.7

Drainage

Well Drained

Foxglove Planting Risk Windows

Early Start (70% safe) ✓ Fits season (178 days to spare)
Start indoors: Jan 9 Transplant: Feb 27 🌸 Bloom: Apr 17 – May 15
Recommended (50%) ✓ Fits season (177 days to spare)
Start indoors: Jan 17 Transplant: Mar 7 🌸 Bloom: Apr 25 – May 23
Safe Start (90%) ✓ Fits season (169 days to spare)
Start indoors: Feb 8 Transplant: Mar 29 🌸 Bloom: May 17 – Jun 14

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 Cass County

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

Soil pH

Your soil pH (5.6–6.7) overlaps with Foxglove's range (5.5–6.5), though not a perfect match.

Soil Texture

Sandy soil in Cass County warms quickly in spring but drains fast. Foxglove will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Foxglove.

Organic Matter

Organic matter is low (1.9%). Add 2-3 inches of compost before planting Foxglove.

How to Plant Foxglove

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

Succession Planting Foxglove

3
successive plantings in your 247-day season

Sow every 9.1 weeks. Last sowing by Jul 19 to harvest before frost.

Foxglove Water Budget

Plant needs
1.0″/week
Rainfall provides
1.2″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 178 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 2" 0" ❄️ Dormant
Feb 2.5" 0" ❄️ Dormant
Mar 4.3" 4.3" 0" ✅ Rainfall sufficient
Apr 4.3" 6.6" 0" ✅ Rainfall sufficient
May 4.3" 11.3" 0" ✅ Rainfall sufficient
Jun 4.3" 12.4" 0" ✅ Rainfall sufficient
Jul 4.3" 8.9" 0" ✅ Rainfall sufficient
Aug 4.3" 8.7" 0" ✅ Rainfall sufficient
Sep 4.3" 6.7" 0" ✅ Rainfall sufficient
Oct 4.3" 4.3" 0" ✅ Rainfall sufficient
Nov 4.3" 2.4" 1.9" 💧 Light watering
Dec 1.7" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Cass 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 ~2,050 GDD — county provides 5,063 GDD Excellent fit

Foxglove Planting Timeline — Cass County, TX

Foxglove Planting Calendar

Activity When Date Range
Start Indoors January 17 Jan 17 – Jan 31
Transplant Outdoors March 7 Mar 7 – Mar 21
Direct Sow March 7 Mar 7 – Mar 28
Bloom April 25 Apr 25 – May 23

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

Month-by-Month Timeline

MonthActivities
January Start Indoors
February
March Transplant Outdoors Direct Sow
April Bloom
May Bloom
June
July
August
September
October
November
December
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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 8b

📆 Growing Season

247 days in Cass County

Growing Tips for Foxglove in Cass County

Direct sow Foxglove outdoors after March 14 in Cass County when soil has warmed and frost danger has passed.

Sandy soil in Cass 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 →

Frequently Asked Questions

When should I plant Foxglove in Cass County, TX?

Cass County is in Zone 8b with an average last frost of March 14. Plan your Foxglove planting based on this frost date — see the calendar above for exact timing.

What planting zone is Cass County, TX?

Cass County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 14 and first fall frost is November 16.

🌱

Your Cass County Garden Planner — Free

A 22-page printable planner built for Cass County (Zone 8b). 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 Cass County, TX. Local conditions may vary. Last updated: June 2026.

Sources & credits

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