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When to Plant Foxglove in Howard County, TX

Howard County, Texas Zone 8a June

Your June gardening checklist

We've pulled the most time-sensitive tasks for Howard County, Texas this June and put them front and centre. Tackle them in order.

Avg. last frost March 26
Avg. first frost November 12
Soil temp (4") 68°F
Watering High
Pest pressure High
Daylight 14.1 hrs
  1. Collect foxglove at their peak

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

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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.

Howard County, Texas is in USDA Zone 8a. The average last spring frost is March 26 and the first fall frost is November 12, giving you a growing season of approximately 231 days.

At an elevation of 3,918 feet, Howard County receives approximately 59.3 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 99°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. 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
Howard County, TX (Zone 8a) Long season
231 days
Last Spring Frost March 26
231 growing days
First Fall Frost November 12
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Howard County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.9-8.3

Drainage

Well Drained

Foxglove Planting Risk Windows

Early Start (70% safe) ✓ Fits season (153 days to spare)
Start indoors: Jan 21 Transplant: Mar 18 🌸 Bloom: May 6 – Jun 3
Recommended (50%) ✓ Fits season (154 days to spare)
Start indoors: Jan 29 Transplant: Mar 26 🌸 Bloom: May 14 – Jun 11
Safe Start (90%) ✓ Fits season (149 days to spare)
Start indoors: Feb 17 Transplant: Apr 14 🌸 Bloom: Jun 2 – Jun 30

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 Howard County

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

Soil pH

Your soil pH (7.9–8.3) is more alkaline than Foxglove prefers (5.5–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Howard 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 (0.9%). 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 231-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
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

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 4.6" 0" ❄️ Dormant
Feb 3.3" 0" ❄️ Dormant
Mar 4.3" 3.2" 1.1" 💧 Light watering
Apr 4.3" 2.3" 2" 💧 Light watering
May 4.3" 1.5" 2.8" 🚿 Regular watering
Jun 4.3" 2" 2.3" 🚿 Regular watering
Jul 4.3" 10.3" 0" ✅ Rainfall sufficient
Aug 4.3" 11.5" 0" ✅ Rainfall sufficient
Sep 4.3" 8.2" 0" ✅ Rainfall sufficient
Oct 4.3" 5.2" 0" ✅ Rainfall sufficient
Nov 4.3" 3.5" 0.8" 💧 Light watering
Dec 3.6" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Howard 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 ~2,425 GDD — county provides 5,601 GDD Excellent fit

Foxglove Planting Timeline — Howard County, TX

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

MonthActivities
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
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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 8a

📆 Growing Season

231 days in Howard County

Growing Tips for Foxglove in Howard County

Direct sow Foxglove outdoors after March 26 in Howard County when soil has warmed and frost danger has passed.

Sandy soil in Howard County dries quickly — mulch Foxglove with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 99°F in Howard County, provide afternoon shade for Foxglove and water deeply in the morning.

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 Howard County, TX?

Howard 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 Howard County, TX?

Howard County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 26 and first fall frost is November 12.

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Your Howard County Garden Planner — Free

A 22-page printable planner built for Howard 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.

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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 Howard 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.