When to plant Sweet Pea in Greene County, IL
Greene County's climate puts the Sweet Pea spring window between March 9 and March 30. time plantings around the expected last-frost window for best survival.
When to Plant Sweet Pea in Greene County, IL
June in the garden — Greene County, Illinois
Welcome to June in Zone 6a. These are the moves that will have the biggest impact on your growing season.
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.
Greene County, Illinois is in USDA Zone 6a. The average last spring frost is April 13 and the first fall frost is October 21, giving you a growing season of approximately 191 days.
At an elevation of 1,248 feet, Greene County receives approximately 37 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Sweet Pea during the growing season.
Greene County Soil Profile
Soil Type
Silt Loam
Soil pH
6.1-6.7
Drainage
Well Drained
Sweet Pea Planting Risk Windows
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 Greene County
How your county's soil matches Sweet Pea's growing requirements.
Soil pH
Your soil pH (6.1–6.7) is more acidic than Sweet Pea prefers (7.0–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Greene County is excellent for Sweet Pea — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Sweet Pea.
Organic Matter
Organic matter is excellent (4.5%) — Sweet Pea will thrive.
How to Plant Sweet Pea
Succession Planting Sweet Pea
Sow every 7.4 weeks. Last sowing by Jul 28 to harvest before frost.
Sweet Pea Water Budget
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 | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.7" | 0" | ❄️ Dormant |
| Mar | — | 2.7" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| May | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Jun | 4.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Aug | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 3.3" | 1" | 💧 Light watering |
| Oct | 4.3" | 3" | 1.3" | 💧 Light watering |
| Nov | — | 2.6" | 0" | ❄️ Dormant |
| Dec | — | 2.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Greene 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 Planting Timeline — Greene County, IL
Sweet Pea Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 2 | Mar 2 – Mar 16 |
| Transplant Outdoors | April 13 | Apr 13 – Apr 27 |
| Direct Sow | March 9 | Mar 9 – Mar 30 |
| Bloom | June 29 | Jun 29 – Sep 7 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors |
| May | — |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| 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_acidic
🗺️ USDA Zone
Zone 6a
📆 Growing Season
191 days in Greene County
Growing Tips for Sweet Pea in Greene County
Direct sow Sweet Pea outdoors after April 13 in Greene 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 →
Sweet Pea in Other Locations
Frequently Asked Questions
When should I plant Sweet Pea in Greene County, IL?
Greene County is in Zone 6a with an average last frost of April 13. Plan your Sweet Pea planting based on this frost date — see the calendar above for exact timing.
What planting zone is Greene County, IL?
Greene County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 13 and first fall frost is October 21.
When should I plant Sweet Pea in Greene County, IL?
In Greene County, IL, plant Sweet Pea after the last frost (around April 13) and before the first frost (around October 21). Best results when soil holds above 50°F.
What growing zone is Greene County, IL for Sweet Pea?
Greene 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 Greene County's climate?
Yes — Sweet Pea grows well in Greene County's temperate climate. Greene County averages a 191-day frost-free season, with last frost around April 13 and first frost around October 21.
Your Greene County Garden Planner — Free
A 22-page printable planner built for Greene 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.