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When to Plant Foxglove in Hamilton County, TX

Hamilton County, Texas Zone 8b June

Your June planting checklist for Hamilton County, Texas

If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.

Avg. last frost March 18
Avg. first frost November 12
Soil temp (4") 71°F
Watering Low
Pest pressure High
Daylight 14.1 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.

Hamilton County, Texas is in USDA Zone 8b. The average last spring frost is March 18 and the first fall frost is November 12, giving you a growing season of approximately 239 days.

At an elevation of 4,378 feet, Hamilton County receives approximately 65.2 inches of rainfall annually with predominantly clay soil. Summer highs average 93°F, providing good warmth for Foxglove during the growing season. Clay soil retains moisture well for Foxglove, but amend with compost to improve drainage and prevent root rot. 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
Hamilton County, TX (Zone 8b) Long season
239 days
Last Spring Frost March 18
239 growing days
First Fall Frost November 12

Hamilton County Soil Profile

Soil Type

Clay

Soil pH

6.9-8.2

Drainage

Well Drained

Foxglove Planting Risk Windows

Early Start (70% safe) ✓ Fits season (174 days to spare)
Start indoors: Jan 10 Transplant: Feb 28 🌸 Bloom: Apr 18 – May 16
Recommended (50%) ✓ Fits season (169 days to spare)
Start indoors: Jan 21 Transplant: Mar 11 🌸 Bloom: Apr 29 – May 27
Safe Start (90%) ✓ Fits season (164 days to spare)
Start indoors: Feb 14 Transplant: Apr 4 🌸 Bloom: May 23 – Jun 20

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 Hamilton County

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

Soil pH

Your soil pH (6.9–8.2) is more alkaline than Foxglove prefers (5.5–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

Your clay soil in Hamilton County is workable for Foxglove. Add compost annually to improve structure.

Organic Matter

Organic matter is moderate (3.4%). Annual compost additions will help Foxglove.

How to Plant Foxglove

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

Succession Planting Foxglove

3
successive plantings in your 239-day season

Sow every 9.1 weeks. Last sowing by Jul 15 to harvest before frost.

Foxglove Water Budget

Plant needs
1.0″/week
Rainfall provides
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

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 1.6" 0" ❄️ Dormant
Feb 2.2" 0" ❄️ Dormant
Mar 4.3" 3.8" 0.5" 💧 Light watering
Apr 4.3" 6.9" 0" ✅ Rainfall sufficient
May 4.3" 9.7" 0" ✅ Rainfall sufficient
Jun 4.3" 10.8" 0" ✅ Rainfall sufficient
Jul 4.3" 8.7" 0" ✅ Rainfall sufficient
Aug 4.3" 8.5" 0" ✅ Rainfall sufficient
Sep 4.3" 5.7" 0" ✅ Rainfall sufficient
Oct 4.3" 3.7" 0.6" 💧 Light watering
Nov 4.3" 2.2" 2.1" 💧 Light watering
Dec 1.6" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Hamilton 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 ~1,975 GDD — county provides 4,720 GDD Excellent fit

Foxglove Planting Timeline — Hamilton County, TX

Foxglove Planting Calendar

Activity When Date Range
Start Indoors January 21 Jan 21 – Feb 4
Transplant Outdoors March 11 Mar 11 – Mar 25
Direct Sow March 11 Mar 11 – Apr 1
Bloom April 29 Apr 29 – May 27

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

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Start Indoors
March Transplant Outdoors Direct Sow
April Direct Sow Bloom
May Bloom
June
July
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 8b

📆 Growing Season

239 days in Hamilton County

Growing Tips for Foxglove in Hamilton County

Direct sow Foxglove outdoors after March 18 in Hamilton County when soil has warmed and frost danger has passed.

With Hamilton County's clay soil (40% clay), work in 3-4 inches of compost before planting Foxglove. Avoid tilling when soil is wet to prevent compaction.

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 Hamilton County, TX?

Hamilton County is in Zone 8b with an average last frost of March 18. Plan your Foxglove planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hamilton County, TX?

Hamilton County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 18 and first fall frost is November 12.

🌱

Your Hamilton County Garden Planner — Free

A 22-page printable planner built for Hamilton 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 Hamilton County, TX. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.