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When to Plant Sweet Pea in Carson County, TX

Carson County, Texas Zone 7a June

Your June game plan for Carson County, Texas

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

Avg. last frost April 14
Avg. first frost October 25
Soil temp (4") 71°F
Watering High
Pest pressure High
Daylight 14.4 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.

Carson County, Texas is in USDA Zone 7a. The average last spring frost is April 14 and the first fall frost is October 25, giving you a growing season of approximately 194 days.

At an elevation of 2,585 feet, Carson County receives approximately 45.2 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 99°F, so Sweet Pea may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Sweet Pea will need more frequent watering and organic matter to retain nutrients.

Annual Blooms in Spring Pollinator-friendly Good for cutting Fragrant
Carson County, TX (Zone 7a) Moderate season
194 days
Last Spring Frost April 14
194 growing days
First Fall Frost October 25

Carson County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.9-8.8

Drainage

Well Drained

Sweet Pea Planting Risk Windows

Early Start (70% safe) ✓ Fits season (39 days to spare)
Transplant: Apr 8 🌸 Bloom: Jun 17 – Sep 9
Recommended (50%) ✓ Fits season (40 days to spare)
Transplant: Apr 14 🌸 Bloom: Jun 23 – Sep 15
Safe Start (90%) ✓ Fits season (36 days to spare)
Transplant: May 1 🌸 Bloom: Jul 10 – Oct 2

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 Carson County

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

Soil pH

Your soil pH (7.9–8.8) is more alkaline than Sweet Pea prefers (7.0–7.5). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Sweet Pea.

Organic Matter

Organic matter is low (1.0%). Add 2-3 inches of compost before planting Sweet Pea.

How to Plant Sweet Pea

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

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Sweet Pea

3
successive plantings in your 194-day season

Sow every 7.4 weeks. Last sowing by Aug 01 to harvest before frost.

For a dedicated fall crop, sow by Aug 30.

Sweet Pea Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 666 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 3.5" 0" ❄️ Dormant
Feb 2.5" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 4.3" 1.3" 3" 🚿 Regular watering
May 4.3" 1.1" 3.2" 🚿 Regular watering
Jun 4.3" 1.4" 2.9" 🚿 Regular watering
Jul 4.3" 7.6" 0" ✅ Rainfall sufficient
Aug 4.3" 9" 0" ✅ Rainfall sufficient
Sep 4.3" 6.6" 0" ✅ Rainfall sufficient
Oct 4.3" 4.1" 0.2" 💧 Light watering
Nov 2.6" 0" ❄️ Dormant
Dec 3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Carson 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 ~1,819 GDD — county provides 4,704 GDD Excellent fit

Sweet Pea Planting Timeline — Carson County, TX

Sweet Pea Planting Calendar

Activity When Date Range
Direct Sow March 10 Mar 10 – Mar 31
Bloom May 19 May 19 – Aug 11
Fall Sowing August 30 Aug 30 – Sep 13

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

65–85 days

🧪 Soil pH

Needs 7–7.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 7a

📆 Growing Season

194 days in Carson County

Growing Tips for Sweet Pea in Carson County

Direct sow Sweet Pea outdoors after April 14 in Carson County when soil has warmed and frost danger has passed.

Sandy soil in Carson County dries quickly — mulch Sweet Pea 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 Carson County, provide afternoon shade for Sweet Pea and water deeply in the morning.

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 Carson County, TX?

Carson County is in Zone 7a with an average last frost of April 14. Plan your Sweet Pea planting based on this frost date — see the calendar above for exact timing.

What planting zone is Carson County, TX?

Carson County, Texas is in USDA Hardiness Zone 7a. The average last spring frost is April 14 and first fall frost is October 25.

🌱

Your Carson County Garden Planner — Free

A 22-page printable planner built for Carson County (Zone 7a). 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 Carson 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.