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When to Plant Sweet Pea in Upton County, TX

Upton County, Texas Zone 8b June

Your June gardening checklist

Here's what deserves your attention in Upton County, Texas this month. Everything below is tailored to Zone 8b and timed around your local frost dates.

Avg. last frost March 20
Avg. first frost November 12
Soil temp (4") 76°F
Watering High
Pest pressure High
Daylight 14 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.

Upton County, Texas is in USDA Zone 8b. The average last spring frost is March 20 and the first fall frost is November 12, giving you a growing season of approximately 237 days.

At an elevation of 1,734 feet, Upton County receives approximately 50.9 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°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. 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
Upton County, TX (Zone 8b) Long season
237 days
Last Spring Frost March 20
237 growing days
First Fall Frost November 12

Upton County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.8-8.3

Drainage

Well Drained

Sweet Pea Planting Risk Windows

Early Start (70% safe) ✓ Fits season (98 days to spare)
Transplant: Mar 10 🌸 Bloom: May 19 – Jul 28
Recommended (50%) ✓ Fits season (97 days to spare)
Transplant: Mar 20 🌸 Bloom: May 29 – Aug 7
Safe Start (90%) ✓ Fits season (90 days to spare)
Transplant: Apr 13 🌸 Bloom: Jun 22 – Aug 31

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 Upton County

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

Soil pH

Your soil pH (7.8–8.3) is more alkaline than Sweet Pea prefers (7.0–7.5). Add sulfur or peat moss to lower pH.

Soil Texture

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

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 9 weeks before your first frost date for a fall harvest.

Succession Planting Sweet Pea

4
successive plantings in your 237-day season

Sow every 7.4 weeks. Last sowing by Aug 19 to harvest before frost.

For a dedicated fall crop, sow by Sep 10.

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 248 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 3.9" 0" ❄️ Dormant
Feb 2.5" 0" ❄️ Dormant
Mar 4.3" 3.2" 1.1" 💧 Light watering
Apr 4.3" 2" 2.3" 🚿 Regular watering
May 4.3" 1.3" 3" 🚿 Regular watering
Jun 4.3" 1.7" 2.6" 🚿 Regular watering
Jul 4.3" 8.4" 0" ✅ Rainfall sufficient
Aug 4.3" 9.8" 0" ✅ Rainfall sufficient
Sep 4.3" 7.7" 0" ✅ Rainfall sufficient
Oct 4.3" 4.4" 0" ✅ Rainfall sufficient
Nov 4.3" 2.7" 1.6" 💧 Light watering
Dec 3.4" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Upton 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 ~1,650 GDD — county provides 5,214 GDD Excellent fit

Sweet Pea Planting Timeline — Upton County, TX

Sweet Pea Planting Calendar

Activity When Date Range
Bloom November 19 Nov 19 – Jan 28
Fall Sowing September 10 Sep 10 – Sep 24

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: too_alkaline

🗺️ USDA Zone

Zone 8b

📆 Growing Season

237 days in Upton County

Growing Tips for Sweet Pea in Upton County

Direct sow Sweet Pea outdoors after March 20 in Upton County when soil has warmed and frost danger has passed.

Sandy soil in Upton 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 96°F in Upton 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 Upton County, TX?

Upton County is in Zone 8b with an average last frost of March 20. Plan your Sweet Pea planting based on this frost date — see the calendar above for exact timing.

What planting zone is Upton County, TX?

Upton County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 20 and first fall frost is November 12.

🌱

Your Upton County Garden Planner — Free

A 22-page printable planner built for Upton 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 Upton 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.