When to plant Lobelia in Simpson County, KY
In Simpson County, Lobelia is a spring-only crop. Plant March 16–March 30 once soil hits 50°F.
When to Plant Lobelia in Simpson County, KY
Your June gardening checklist
A quick June briefing for Simpson County, Kentucky gardeners — what's urgent, what's next, and what can wait.
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Time to start lobelia inside
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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Basket week: lobelia
Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.
Before July arrives, get these ready
- 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.
Simpson County, Kentucky is in USDA Zone 7a. The average last spring frost is April 6 and the first fall frost is October 29, giving you a growing season of approximately 206 days.
At an elevation of 3,996 feet, Simpson County receives approximately 49.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Lobelia during the growing season.
Simpson County Soil Profile
Soil Type
Silt Loam
Soil pH
5.5-6.7
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 Simpson County
How your county's soil matches Lobelia's growing requirements.
Soil pH
Your soil pH (5.5–6.7) overlaps with Lobelia's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Simpson County is excellent for Lobelia — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Lobelia.
Organic Matter
Organic matter is moderate (2.5%). Annual compost additions will help Lobelia.
How to Plant Lobelia
Succession Planting Lobelia
Sow every 8 weeks. Last sowing by Aug 10 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 | — | 4.1" | 0" | ❄️ Dormant |
| Feb | — | 3.9" | 0" | ❄️ Dormant |
| Mar | — | 3.9" | 0" | ❄️ Dormant |
| Apr | 4.3" | 4" | 0.3" | 💧 Light watering |
| May | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Jun | 4.3" | 4.6" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 5.6" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.9" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Oct | 4.3" | 2.9" | 1.4" | 💧 Light watering |
| Nov | — | 4" | 0" | ❄️ Dormant |
| Dec | — | 4.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Simpson 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 — Simpson County, KY
Lobelia Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 2 | Feb 2 – Feb 16 |
| Transplant Outdoors | March 16 | Mar 16 – Mar 30 |
| Bloom | May 11 | May 11 – Aug 3 |
· 6" apart · Rows 8" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Transplant Outdoors |
| April | — |
| May | Bloom |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1"/week · Natural rainfall sufficient
📅 Days to Maturity
70–80 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 7a
📆 Growing Season
206 days in Simpson County
Growing Tips for Lobelia in Simpson County
Direct sow Lobelia outdoors after April 06 in Simpson 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
Frequently Asked Questions
When should I plant Lobelia in Simpson County, KY?
Simpson County is in Zone 7a with an average last frost of April 6. Plan your Lobelia planting based on this frost date — see the calendar above for exact timing.
What planting zone is Simpson County, KY?
Simpson County, Kentucky is in USDA Hardiness Zone 7a. The average last spring frost is April 6 and first fall frost is October 29.
When should I plant Lobelia in Simpson County, KY?
In Simpson County, KY, plant Lobelia after the last frost (around April 6) and before the first frost (around October 29). Best results when soil holds above 50°F.
What growing zone is Simpson County, KY for Lobelia?
Simpson County sits in USDA Zone 7a. Lobelia grows reliably in zones 3a through 9b, so it's a good fit here.
Can Lobelia grow in Simpson County's climate?
Yes — Lobelia grows well in Simpson County's temperate climate. Simpson County averages a 206-day frost-free season, with last frost around April 6 and first frost around October 29.
Your Simpson County Garden Planner — Free
A 22-page printable planner built for Simpson County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.