When to plant Begonias in Warren County, IL
Warren County's short 191-day growing season means one Begonias planting between April 20 and May 4. No fall crop in Zone 5b.
When to Plant Begonias in Warren County, IL
Your June planting checklist for Warren County, Illinois
June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Warren County, Illinois.
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Fire up the seed-starting tray: begonias
Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.
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Bring in the begonias
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
To set up a strong July, finish these tasks
- First harvests: begonias
Wax begonias (Begonia × semperflorens) are the workhorse shade bedding plant of American horticulture, offering continuous bloom from transplant to hard frost. Bronze or green-leaved varieties perform well from deep shade to full sun (in northern zones) and tolerate summer humidity better than most cool- season flowers. A staple of mass plantings, containers, and window boxes.
Warren County, Illinois is in USDA Zone 5b. 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 801 feet, Warren County receives approximately 36.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Begonias during the growing season.
Warren County Soil Profile
Soil Type
Silt Loam
Soil pH
5.9-6.8
Drainage
Well Drained
Begonias 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 Warren County
How your county's soil matches Begonias's growing requirements.
Soil pH
Your soil pH (5.9–6.8) overlaps with Begonias's range (5.5–6.5), though not a perfect match.
Soil Texture
The silt loam soil in Warren County is excellent for Begonias — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.0%) — Begonias will thrive.
How to Plant Begonias
Succession Planting Begonias
Sow every 8 weeks. Last sowing by Jul 23 to harvest before frost.
Begonias Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Begonias
Begonias needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Begonias Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.6" | 0" | ❄️ Dormant |
| Mar | — | 2.4" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| May | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Jun | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 3.3" | 1" | 💧 Light watering |
| Sep | 4.3" | 3" | 1.3" | 💧 Light watering |
| Oct | 4.3" | 2.9" | 1.4" | 💧 Light watering |
| Nov | — | 2.8" | 0" | ❄️ Dormant |
| Dec | — | 2.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Warren County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Begonias 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.
Begonias Planting Timeline — Warren County, IL
Begonias Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 2 | Feb 2 – Feb 16 |
| Transplant Outdoors | April 20 | Apr 20 – May 4 |
| Bloom | June 29 | Jun 29 – Sep 21 |
· 8" apart · Rows 10" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | — |
| April | Transplant Outdoors |
| May | Transplant Outdoors |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
70–90 days
🧪 Soil pH
Needs 5.5–6.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 5b
📆 Growing Season
191 days in Warren County
Growing Tips for Begonias in Warren County
Direct sow Begonias outdoors after April 13 in Warren County when soil has warmed and frost danger has passed.
General growing tips
Start seeds indoors 10–12 weeks before last frost — seed is dust-fine; surface-sow on moist mix under lights, do not cover. Bottom heat (70–75°F) speeds germination. Transplant after frost; begonias are not direct-sown in practice. Pinch seedlings once for branching. Keep soil evenly moist; avoid waterlogged conditions. Bronze-leaf types tolerate more sun; green- leaf types prefer shade to part-sun.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Begonias in Other Locations
Frequently Asked Questions
When should I plant Begonias in Warren County, IL?
Warren County is in Zone 5b with an average last frost of April 13. Plan your Begonias planting based on this frost date — see the calendar above for exact timing.
What planting zone is Warren County, IL?
Warren County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 13 and first fall frost is October 21.
When should I plant Begonias in Warren County, IL?
In Warren County, IL, plant Begonias 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 Warren County, IL for Begonias?
Warren County sits in USDA Zone 5b. Begonias grows reliably in zones 2a through 11b, so it's a good fit here.
Can Begonias grow in Warren County's climate?
Yes — Begonias grows well in Warren County's temperate climate. Warren County averages a 191-day frost-free season, with last frost around April 13 and first frost around October 21.
Your Warren County Garden Planner — Free
A 22-page printable planner built for Warren 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.