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When to plant Sweet Pea in Logan County, IL

For Logan County, gardeners: plant Sweet Pea March 11 through April 1 once soil reads 50°F.

When to Plant Sweet Pea in Logan County, IL

Logan County, Illinois Zone 6a June

Top priorities for Logan County, Illinois gardeners in June

Your garden in Logan County, Illinois is working on a schedule, even when you're not. Here's where you should be this June.

Avg. last frost April 15
Avg. first frost October 16
Soil temp (4") 70°F
Watering Low
Pest pressure High
Daylight 14.8 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.

Logan County, Illinois is in USDA Zone 6a. The average last spring frost is April 15 and the first fall frost is October 16, giving you a growing season of approximately 184 days.

At an elevation of 1,132 feet, Logan County receives approximately 39.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°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
Logan County, IL (Zone 6a) Moderate season
184 days
Last Spring Frost April 15
184 growing days
First Fall Frost October 16

Logan County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.7

Drainage

Well Drained

Sweet Pea Planting Risk Windows

Early Start (70% safe) ✓ Fits season (36 days to spare)
Start indoors: Feb 26 Transplant: Apr 9 🌸 Bloom: Jun 25 – Sep 3
Recommended (50%) ✓ Fits season (37 days to spare)
Start indoors: Mar 4 Transplant: Apr 15 🌸 Bloom: Jul 1 – Sep 9
Safe Start (90%) ✓ Fits season (43 days to spare)
Start indoors: Mar 12 Transplant: Apr 23 🌸 Bloom: Jul 9 – Sep 17

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 Logan County

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

Soil pH

Your soil pH (6.0–6.7) is more acidic than Sweet Pea prefers (7.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.2%) — Sweet Pea will thrive.

How to Plant Sweet Pea

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

Succession Planting Sweet Pea

3
successive plantings in your 184-day season

Sow every 7.4 weeks. Last sowing by Jul 23 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 146 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 1.6" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 4.3" 3.6" 0.7" 💧 Light watering
May 4.3" 5" 0" ✅ Rainfall sufficient
Jun 4.3" 5.4" 0" ✅ Rainfall sufficient
Jul 4.3" 5" 0" ✅ Rainfall sufficient
Aug 4.3" 3.9" 0.4" 💧 Light watering
Sep 4.3" 3.5" 0.8" 💧 Light watering
Oct 4.3" 2.7" 1.6" 💧 Light watering
Nov 2.7" 0" ❄️ Dormant
Dec 2.4" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Logan 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 ~919 GDD — county provides 2,254 GDD Excellent fit

Sweet Pea Planting Timeline — Logan County, IL

Sweet Pea Planting Calendar

Activity When Date Range
Start Indoors March 4 Mar 4 – Mar 18
Transplant Outdoors April 15 Apr 15 – Apr 29
Direct Sow March 11 Mar 11 – Apr 1
Bloom July 1 Jul 1 – Sep 9

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

Month-by-Month Timeline

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

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 6a

📆 Growing Season

184 days in Logan County

Growing Tips for Sweet Pea in Logan County

Direct sow Sweet Pea outdoors after April 15 in Logan 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 Logan County, IL?

Logan County is in Zone 6a with an average last frost of April 15. Plan your Sweet Pea planting based on this frost date — see the calendar above for exact timing.

What planting zone is Logan County, IL?

Logan County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 15 and first fall frost is October 16.

When should I plant Sweet Pea in Logan County, IL?

In Logan County, IL, plant Sweet Pea after the last frost (around April 15) and before the first frost (around October 16). Best results when soil holds above 50°F.

What growing zone is Logan County, IL for Sweet Pea?

Logan County sits in USDA Zone 6a. Sweet Pea grows reliably in zones 2a through 9b, so it's a good fit here.

Can Sweet Pea grow in Logan County's climate?

Yes — Sweet Pea grows well in Logan County's temperate climate. Logan County averages a 184-day frost-free season, with last frost around April 15 and first frost around October 16.

🌱

Your Logan County Garden Planner — Free

A 22-page printable planner built for Logan County (Zone 6a). 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 Logan County, IL. 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.