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When to Plant Alliums in Harrison County, TX

Harrison County, Texas Zone 8b June

What to do in June

June is a pivotal month for Harrison County, Texas gardens. Focus on these tasks first and you'll set up the rest of the season for success.

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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Ornamental alliums (Allium spp.) bridge the gap between spring and summer with their striking globe-shaped flower heads in shades of purple, violet, white, and pink. Blooming after tulips have faded, they extend the spring display well into early summer. 'Gladiator', 'Globemaster', and 'Purple Sensation' produce softball-sized heads on 18–36 inch stems, while smaller species create charming accents at border fronts. Deer and rodents shun them completely due to the characteristic onion scent. Dried seed heads provide architectural interest into fall.

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 Alliums may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Alliums will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Alliums root diseases.

Bulb 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

Alliums Planting Risk Windows

Early Start (70% safe) ✓ Fits season (195 days to spare)
Transplant: Mar 5 🌸 Bloom: Apr 2 – Apr 23
Recommended (50%) ✓ Fits season (197 days to spare)
Transplant: Mar 13 🌸 Bloom: Apr 10 – May 1
Safe Start (90%) ✓ Fits season (190 days to spare)
Transplant: Apr 5 🌸 Bloom: May 3 – May 24

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 Alliums's growing requirements.

Soil pH

Your soil pH (5.3–6.8) overlaps with Alliums's range (5.5–7.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Alliums.

Organic Matter

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

How to Plant Alliums

5"
Planting Depth
7"
Between Plants
8"
Between Rows

Fall planting: Sow 4 weeks before your first frost date for a fall harvest.

Succession Planting Alliums

10
successive plantings in your 246-day season

Sow every 3.1 weeks. Last sowing by Oct 03 to harvest before frost.

For a dedicated fall crop, sow by Oct 17.

Alliums Water Budget

Plant needs
0.5″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Alliums

Alliums needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Alliums Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 2.2" 4.4" 0" ✅ Rainfall sufficient
Apr 2.2" 6" 0" ✅ Rainfall sufficient
May 2.2" 9.7" 0" ✅ Rainfall sufficient
Jun 2.2" 11" 0" ✅ Rainfall sufficient
Jul 2.2" 7.9" 0" ✅ Rainfall sufficient
Aug 2.2" 7.3" 0" ✅ Rainfall sufficient
Sep 2.2" 6.3" 0" ✅ Rainfall sufficient
Oct 2.2" 4" 0" ✅ Rainfall sufficient
Nov 2.2" 2.3" 0" ✅ Rainfall sufficient
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.

Alliums 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.

Alliums needs ~770 GDD — county provides 5,412 GDD Excellent fit

Alliums Planting Timeline — Harrison County, TX

Alliums Planting Calendar

Activity When Date Range
Bloom November 14 Nov 14 – Dec 5
Fall Sowing October 17 Oct 17 – Oct 31

Plant 5" deep · 7" apart · Rows 8" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May
June
July
August
September
October Fall Sowing
November Bloom
December Bloom
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

28–42 days

🧪 Soil pH

Needs 5.5–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 8b

📆 Growing Season

246 days in Harrison County

Growing Tips for Alliums in Harrison County

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

Sandy soil in Harrison County dries quickly — mulch Alliums 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 Alliums and water deeply in the morning.

Your generous 246.0-day season in Harrison County allows multiple plantings of Alliums. Sow every 14.0 days for continuous harvest.

Common pests for Alliums in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.

General growing tips

Plant bulbs in fall, 3–4 times as deep as the bulb diameter (typically 4–6 inches for large types, 3 inches for small species). Space 6–8 inches apart for standard cultivars. Foliage often looks untidy as it dies back before bloom — plant around perennials that will conceal the yellowing leaves. Excellent drainage is essential; alliums rot in wet soils. Leave bulbs in place for naturalization; divide every 3–4 years when clusters become congested. Deadhead spent globes or leave for ornamental seedheads and self-sowing.

Companion Planting

Good Companions

Avoid Planting Near

  • Beans
  • Peas

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Alliums in Harrison County, TX?

Harrison County is in Zone 8b with an average last frost of March 13. Plan your Alliums 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.