When to plant Lobelia in Mapleton, IL
In Mapleton, Lobelia is a spring-only crop. Plant April 9–April 23 once soil hits 50°F.
When to Plant Lobelia in Mapleton, IL
July in Peoria County, Illinois — your action list
Each item below is timed to Peoria County, Illinois's frost dates and soil temperatures. Skip nothing, stress about nothing.
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Start harvesting lobelia
This is the payoff month. Bring a basket, bring a friend, and get into the beds.
Get ahead of August
- First harvests: lobelia
Lobelia (Lobelia erinus) is a cool-season annual prized for the intense cobalt blue that is rare among bedding flowers. It blooms most prolifically in spring and early summer but stalls or dies back during heat peaks above 90°F. In zones 3–7 it delivers a long display; in zones 8–9 it is best treated as a spring annual that fades by midsummer. Trailing types cascade beautifully from containers and window boxes.
Mapleton, Illinois is in USDA Zone 6a. The average last spring frost is April 23 and the first fall frost is October 12, giving you a growing season of approximately 172 days.
At an elevation of 884 feet, Peoria County receives approximately 33 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Lobelia during the growing season.
Mapleton Soil Profile
Soil Type
Silt Loam
Soil pH
6.1-7
Drainage
Well Drained
Lobelia 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 Mapleton
How your county's soil matches Lobelia's growing requirements.
Soil pH
Your soil pH (6.1–7.0) is within Lobelia's preferred range (6.0–7.0).
Soil Texture
The silt loam soil in Peoria County is excellent for Lobelia — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.7%) — Lobelia will thrive.
How to Plant Lobelia
Succession Planting Lobelia
Sow every 8 weeks. Last sowing by Jul 24 to harvest before frost.
Lobelia Water Budget
Monthly Watering Guide for Lobelia
Lobelia needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Lobelia Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.4" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| May | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Jun | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Jul | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Aug | 4.3" | 3.4" | 0.9" | 💧 Light watering |
| Sep | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Oct | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| Nov | — | 1.9" | 0" | ❄️ Dormant |
| Dec | — | 1.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Peoria County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Lobelia 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.
Lobelia Planting Timeline — Mapleton, IL
Lobelia Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 19 | Feb 19 – Mar 5 |
| Transplant Outdoors | April 9 | Apr 9 – Apr 23 |
| Bloom | June 4 | Jun 4 – Aug 27 |
· 6" apart · Rows 8" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors |
| April | Transplant Outdoors |
| May | — |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
70–80 days
🧪 Soil pH
Needs 6–7 · Your soil: ideal
🗺️ USDA Zone
Zone 6a
📆 Growing Season
172 days in Peoria County
Growing Tips for Lobelia in Mapleton
Direct sow Lobelia outdoors after April 23 in Peoria 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 and requires light to germinate; surface-sow and press gently. Keep at 65–70°F. Not reliably direct-sown. Transplant in cool weather, 2–4 weeks before last frost date is acceptable in zones 5+. Shear plants by one-third after the first bloom flush to encourage a second flush in fall. Provide afternoon shade in zones 7+ to extend bloom into summer.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Lobelia in Other Locations
When should I plant Lobelia in Mapleton, IL?
In Mapleton, IL, plant Lobelia after the last frost (around April 23) and before the first frost (around October 12). Best results when soil holds above 50°F.
What growing zone is Mapleton, IL for Lobelia?
Mapleton sits in USDA Zone 6a. Lobelia grows reliably in zones 3a through 9b, so it's a good fit here.
Can Lobelia grow in Mapleton's climate?
Yes — Lobelia grows well in Mapleton's temperate climate. Mapleton averages a 172-day frost-free season, with last frost around April 23 and first frost around October 12.
Your Peoria County Garden Planner — Free
A 22-page printable planner built for Peoria 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.