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When to Plant Sweet Pea in Hill County, TX

Hill County, Texas Zone 8b June

This month in Hill County, Texas

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

Avg. last frost March 12
Avg. first frost November 19
Soil temp (4") 79°F
Watering Low
Pest pressure High
Daylight 14.1 hrs

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Sweet peas (Lathyrus odoratus) are beloved cool-season climbing annuals grown primarily for their intensely fragrant, ruffled blooms in shades of pink, purple, red, and white. They thrive in cool spring conditions, climbing trellises to 4–6 feet, and make outstanding cut flowers. Bloom ceases once summer heat arrives, making early sowing critical for a long cutting season.

Hill County, Texas is in USDA Zone 8b. The average last spring frost is March 12 and the first fall frost is November 19, giving you a growing season of approximately 252 days.

At an elevation of 2,597 feet, Hill County receives approximately 54.7 inches of rainfall annually with predominantly clay soil. Summer highs average 93°F, providing good warmth for Sweet Pea during the growing season. Clay soil retains moisture well for Sweet Pea, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sweet Pea root diseases.

Annual Blooms in Spring Pollinator-friendly Good for cutting Fragrant
Hill County, TX (Zone 8b) Long season
252 days
Last Spring Frost March 12
252 growing days
First Fall Frost November 19

Hill County Soil Profile

Soil Type

Clay

Soil pH

7.3-7.7

Drainage

Well Drained

Sweet Pea Planting Risk Windows

Early Start (70% safe) ✓ Fits season (111 days to spare)
Transplant: Mar 5 🌸 Bloom: May 14 – Jul 23
Recommended (50%) ✓ Fits season (112 days to spare)
Transplant: Mar 12 🌸 Bloom: May 21 – Jul 30
Safe Start (90%) ✓ Fits season (99 days to spare)
Transplant: Apr 7 🌸 Bloom: Jun 16 – Aug 25

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 Hill County

How your county's soil matches Sweet Pea's growing requirements.

Soil pH

Your soil pH (7.3–7.7) overlaps with Sweet Pea's range (7.0–7.5), though not a perfect match.

Soil Texture

Your clay soil in Hill County is workable for Sweet Pea. Add compost annually to improve structure.

Organic Matter

Organic matter is moderate (2.9%). Annual compost additions will help Sweet Pea.

How to Plant Sweet Pea

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 9 weeks before your first frost date for a fall harvest.

Succession Planting Sweet Pea

4
successive plantings in your 252-day season

Sow every 7.4 weeks. Last sowing by Aug 26 to harvest before frost.

For a dedicated fall crop, sow by Sep 17.

Sweet Pea Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 238 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Sweet Pea

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

Month Sweet Pea Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 4.3" 3.6" 0.7" 💧 Light watering
Apr 4.3" 5.9" 0" ✅ Rainfall sufficient
May 4.3" 6.7" 0" ✅ Rainfall sufficient
Jun 4.3" 9.7" 0" ✅ Rainfall sufficient
Jul 4.3" 7.3" 0" ✅ Rainfall sufficient
Aug 4.3" 7" 0" ✅ Rainfall sufficient
Sep 4.3" 4.8" 0" ✅ Rainfall sufficient
Oct 4.3" 3.5" 0.8" 💧 Light watering
Nov 4.3" 2" 2.3" 🚿 Regular watering
Dec 1.4" 0" ❄️ Dormant

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

Sweet Pea 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.

Sweet Pea needs ~1,481 GDD — county provides 4,977 GDD Excellent fit

Sweet Pea Planting Timeline — Hill County, TX

Sweet Pea Planting Calendar

Activity When Date Range
Bloom November 26 Nov 26 – Feb 4
Fall Sowing September 17 Sep 17 – Oct 1

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

65–85 days

🧪 Soil pH

Needs 7–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 8b

📆 Growing Season

252 days in Hill County

Growing Tips for Sweet Pea in Hill County

Direct sow Sweet Pea outdoors after March 12 in Hill County when soil has warmed and frost danger has passed.

With Hill County's clay soil (36% clay), work in 3-4 inches of compost before planting Sweet Pea. Avoid tilling when soil is wet to prevent compaction.

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

General growing tips

Soak seeds 24 hours before sowing to soften the hard seed coat; nick the seed coat with a file for the fastest germination. In cold zones (2–6), direct-sow as soon as soil can be worked, 4–6 weeks before last frost; seedlings tolerate light frost but not a hard freeze. In zones 7–9, fall-sow 8–10 weeks before first frost for earlier, stronger spring bloom. Provide a trellis or netting from the start. Feed with low-nitrogen, high-potassium fertilizer once buds form. Pick blooms regularly — even one mature seed pod stops flower production. All plant parts are mildly toxic if eaten.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sweet Pea in Hill County, TX?

Hill County is in Zone 8b with an average last frost of March 12. Plan your Sweet Pea planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hill County, TX?

Hill County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 12 and first fall frost is November 19.

🌱

Your Hill County Garden Planner — Free

A 22-page printable planner built for Hill 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 Hill 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.