Blog

When to Plant Sweet Pea in Thomas County, NE

Thomas County, Nebraska Zone 5b June

June to-do list for Thomas County, Nebraska

If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.

Avg. last frost May 10
Avg. first frost October 5
Soil temp (4") 64°F
Watering High
Pest pressure High
Daylight 15 hrs
  1. Get sweet pea seeds going inside

    Label every cell. You will absolutely forget which is which otherwise.

July will be here before you know it — start on
  • First harvests: sweet pea

Instant PDF download. No spam, unsubscribe any time.

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.

Thomas County, Nebraska is in USDA Zone 5b. The average last spring frost is May 10 and the first fall frost is October 5, giving you a growing season of approximately 148 days.

At an elevation of 1,062 feet, Thomas County receives approximately 31.2 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Sweet Pea to ensure they mature before fall.

Annual Blooms in Spring Pollinator-friendly Good for cutting Fragrant
Thomas County, NE (Zone 5b) Short season
148 days
Last Spring Frost May 10
148 growing days
First Fall Frost October 5
Share this guide:

Thomas County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.4

Drainage

Well Drained

Sweet Pea Planting Risk Windows

Early Start (70% safe) ✓ Fits season (7 days to spare)
Start indoors: Mar 23 Transplant: May 4 🌸 Bloom: Jul 20 – Sep 21
Recommended (50%) ✓ Fits season (8 days to spare)
Start indoors: Mar 29 Transplant: May 10 🌸 Bloom: Jul 26 – Sep 27
Safe Start (90%) ✓ Fits season (6 days to spare)
Start indoors: Apr 10 Transplant: May 22 🌸 Bloom: Aug 7 – Oct 9

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 Thomas County

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

Soil pH

Your soil pH (6.2–7.4) is more acidic than Sweet Pea prefers (7.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.6%). Annual compost additions will help Sweet Pea.

How to Plant Sweet Pea

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

Succession Planting Sweet Pea

2
successive plantings in your 148-day season

Sow every 7.4 weeks. Last sowing by Jul 12 to harvest before frost.

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 181 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 2" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 3" 0" ❄️ Dormant
Apr 3.1" 0" ❄️ Dormant
May 4.3" 3.3" 1" 💧 Light watering
Jun 4.3" 2.1" 2.2" 🚿 Regular watering
Jul 4.3" 2.9" 1.4" 💧 Light watering
Aug 4.3" 3.8" 0.5" 💧 Light watering
Sep 4.3" 2.4" 1.9" 💧 Light watering
Oct 4.3" 2.5" 1.8" 💧 Light watering
Nov 2.6" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Thomas 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 ~975 GDD — county provides 1,924 GDD Excellent fit

Sweet Pea Planting Timeline — Thomas County, NE

Sweet Pea Planting Calendar

Activity When Date Range
Start Indoors March 29 Mar 29 – Apr 12
Transplant Outdoors May 10 May 10 – May 24
Direct Sow April 5 Apr 5 – Apr 26
Bloom July 26 Jul 26 – Sep 27

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors Direct Sow
May Transplant Outdoors
June
July Bloom
August Bloom
September Bloom
October
November
December
Share this guide:

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_acidic

🗺️ USDA Zone

Zone 5b

📆 Growing Season

148 days in Thomas County

Growing Tips for Sweet Pea in Thomas County

Direct sow Sweet Pea outdoors after May 10 in Thomas 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 Thomas County, NE?

Thomas County is in Zone 5b with an average last frost of May 10. Plan your Sweet Pea planting based on this frost date — see the calendar above for exact timing.

What planting zone is Thomas County, NE?

Thomas County, Nebraska is in USDA Hardiness Zone 5b. The average last spring frost is May 10 and first fall frost is October 5.

🌱

Your Thomas County Garden Planner — Free

A 22-page printable planner built for Thomas County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Thomas County, NE. 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.