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When to Plant Lupine in Harrison County, TX

Harrison County, Texas Zone 8b June

Your June planting checklist for Harrison County, Texas

Each item below is timed to Harrison County, Texas's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost March 13
Avg. first frost November 14
Soil temp (4") 84°F
Watering Low
Pest pressure High
Daylight 14.1 hrs

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Wild Lupine (Lupinus perennis) is a stunning native perennial of eastern North America, producing tall, densely packed spikes of pea-like flowers in deep blue-purple — the classic wildflower of sandy pine barrens and open woodlands. Russell Hybrid Lupins extend the color range to pink, red, yellow, and bicolors and produce larger flower spikes, making them popular cottage garden perennials. The palmately compound foliage is attractive throughout the season. Wild lupine is the sole larval host plant of the federally endangered Karner Blue butterfly, making it a high-value native planting. Seeds are toxic if ingested. Nitrogen-fixing roots improve surrounding soil over time.

Harrison County, Texas is in USDA Zone 8b. The average last spring frost is March 13 and the first fall frost is November 14, giving you a growing season of approximately 246 days.

At an elevation of 168 feet, Harrison County receives approximately 63.8 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°F, so Lupine may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Lupine will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Lupine root diseases.

Perennial Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Harrison County, TX (Zone 8b) Long season
246 days
Last Spring Frost March 13
246 growing days
First Fall Frost November 14
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Harrison County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.3-6.8

Drainage

Well Drained

Lupine Planting Risk Windows

Early Start (70% safe) ✓ Fits season (167 days to spare)
Start indoors: Jan 8 Transplant: Mar 5 🌸 Bloom: Apr 23 – May 21
Recommended (50%) ✓ Fits season (169 days to spare)
Start indoors: Jan 16 Transplant: Mar 13 🌸 Bloom: May 1 – May 29
Safe Start (90%) ✓ Fits season (162 days to spare)
Start indoors: Feb 8 Transplant: Apr 5 🌸 Bloom: May 24 – Jun 21

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 Harrison County

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

Soil pH

Your soil pH (5.3–6.8) overlaps with Lupine's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Lupine.

Organic Matter

Organic matter is low (1.8%). Add 2-3 inches of compost before planting Lupine.

How to Plant Lupine

0.3"
Planting Depth
18"
Between Plants
24"
Between Rows

Succession Planting Lupine

3
successive plantings in your 246-day season

Sow every 8.6 weeks. Last sowing by Aug 06 to harvest before frost.

Lupine Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 461 gal / 100 sq ft

Monthly Watering Guide for Lupine

Lupine needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Lupine Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 4.3" 4.4" 0" ✅ Rainfall sufficient
Apr 4.3" 6" 0" ✅ Rainfall sufficient
May 4.3" 9.7" 0" ✅ Rainfall sufficient
Jun 4.3" 11" 0" ✅ Rainfall sufficient
Jul 4.3" 7.9" 0" ✅ Rainfall sufficient
Aug 4.3" 7.3" 0" ✅ Rainfall sufficient
Sep 4.3" 6.3" 0" ✅ Rainfall sufficient
Oct 4.3" 4" 0.3" 💧 Light watering
Nov 4.3" 2.3" 2" 💧 Light watering
Dec 1.4" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Harrison County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Lupine 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.

Lupine needs ~1,925 GDD — county provides 5,412 GDD Excellent fit

Lupine Planting Timeline — Harrison County, TX

Lupine Planting Calendar

Activity When Date Range
Start Indoors January 16 Jan 16 – Jan 30
Transplant Outdoors March 13 Mar 13 – Mar 27
Direct Sow March 13 Mar 13 – Apr 3
Bloom May 1 May 1 – May 29

Plant 0.3" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

75–100 days

🧪 Soil pH

Needs 5.5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 8b

📆 Growing Season

246 days in Harrison County

Growing Tips for Lupine in Harrison County

Direct sow Lupine outdoors after March 13 in Harrison County when soil has warmed and frost danger has passed.

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

With summer highs reaching 96°F in Harrison County, provide afternoon shade for Lupine and water deeply in the morning.

Common pests for Lupine in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

Scarify seeds before planting — nick with a file or sandpaper, or soak in warm water for 24 hours — to improve germination. Start in biodegradable pots (peat or paper) 8–10 weeks before last frost to avoid disturbing the taproot at transplant. Direct sowing is equally effective if done fresh in fall (natural stratification and scarification over winter). Transplant or direct-sow after last frost into well-drained, lean soil. Lupines prefer cool, moist springs and decline in summer heat and humidity. They are relatively short-lived in warm zones (treat as biennial in Zones 7–8). Do not over-fertilize — nitrogen-fixers thrive in lean soil. Deadhead after bloom to extend season; allow some pods to mature for self-seeding. Year 2+ plants produce the largest flower spikes.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Lupine in Harrison County, TX?

Harrison County is in Zone 8b with an average last frost of March 13. Plan your Lupine planting based on this frost date — see the calendar above for exact timing.

What planting zone is Harrison County, TX?

Harrison County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 13 and first fall frost is November 14.

🌱

Your Harrison County Garden Planner — Free

A 22-page printable planner built for Harrison 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 Harrison 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.