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When to Plant Sweet Pea in Bexar County, TX

Bexar County, Texas Zone 9a June

Your June gardening checklist

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

Avg. last frost March 11
Avg. first frost November 17
Soil temp (4") 74°F
Watering Low
Pest pressure High
Daylight 13.9 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.

Bexar County, Texas is in USDA Zone 9a. The average last spring frost is March 11 and the first fall frost is November 17, giving you a growing season of approximately 251 days.

At an elevation of 3,197 feet, Bexar County receives approximately 52.1 inches of rainfall annually with predominantly loam soil. Summer highs average 93°F, providing good warmth for Sweet Pea during the growing season. 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
Bexar County, TX (Zone 9a) Long season
251 days
Last Spring Frost March 11
251 growing days
First Fall Frost November 17

Bexar County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.8

Drainage

Well Drained

Sweet Pea Planting Risk Windows

Early Start (70% safe) ✓ Fits season (130 days to spare)
Transplant: Mar 1 🌸 Bloom: May 10 – Jul 5
Recommended (50%) ✓ Fits season (125 days to spare)
Transplant: Mar 11 🌸 Bloom: May 20 – Jul 15
Safe Start (90%) ✓ Fits season (122 days to spare)
Transplant: Apr 7 🌸 Bloom: Jun 16 – Aug 11

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 Bexar County

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

Soil pH

Your soil pH (6.5–7.8) overlaps with Sweet Pea's range (7.0–7.5), though not a perfect match.

Soil Texture

The loam soil in Bexar County is excellent for Sweet Pea — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.2%). 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 10 weeks before your first frost date for a fall harvest.

Succession Planting Sweet Pea

4
successive plantings in your 251-day season

Sow every 7.4 weeks. Last sowing by Aug 24 to harvest before frost.

For a dedicated fall crop, sow by Sep 08.

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 286 gal / 100 sq ft

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 1.4" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 4.3" 3.6" 0.7" 💧 Light watering
Apr 4.3" 5.6" 0" ✅ Rainfall sufficient
May 4.3" 7.5" 0" ✅ Rainfall sufficient
Jun 4.3" 8.2" 0" ✅ Rainfall sufficient
Jul 4.3" 6.3" 0" ✅ Rainfall sufficient
Aug 4.3" 6.3" 0" ✅ Rainfall sufficient
Sep 4.3" 4.9" 0" ✅ Rainfall sufficient
Oct 4.3" 3.5" 0.8" 💧 Light watering
Nov 4.3" 1.9" 2.4" 🚿 Regular watering
Dec 1.3" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Bexar 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 4,957 GDD Excellent fit

Sweet Pea Planting Timeline — Bexar County, TX

Sweet Pea Planting Calendar

Activity When Date Range
Bloom November 17 Nov 17 – Jan 12
Fall Sowing September 8 Sep 8 – Sep 22

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

Month-by-Month Timeline

MonthActivities
January Bloom
February
March
April
May
June
July
August
September Fall Sowing
October
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 9a

📆 Growing Season

251 days in Bexar County

Growing Tips for Sweet Pea in Bexar County

Direct sow Sweet Pea outdoors after March 11 in Bexar County when soil has warmed and frost danger has passed.

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 Bexar County, TX?

Bexar County is in Zone 9a with an average last frost of March 11. Plan your Sweet Pea planting based on this frost date — see the calendar above for exact timing.

What planting zone is Bexar County, TX?

Bexar County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is March 11 and first fall frost is November 17.

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Your Bexar County Garden Planner — Free

A 22-page printable planner built for Bexar County (Zone 9a). 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 Bexar 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.