When to plant Lobelia in DeKalb County County,
In DeKalb County County, Lobelia is a single-season spring crop — there's no second fall window. Plant February 25–March 11 for an 80-day harvest, finishing well before the October 31 first frost.
When to Plant Lobelia in DeKalb County, AL
Your June gardening checklist
If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.
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Collect lobelia at their peak
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
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.
DeKalb County, Alabama is in USDA Zone 8a. The average last spring frost is April 1 and the first fall frost is October 31, giving you a growing season of approximately 213 days.
At an elevation of 393 feet, DeKalb County receives approximately 56.2 inches of rainfall annually with predominantly clay loam soil. Summer highs average 91°F, providing good warmth for Lobelia during the growing season. Clay soil retains moisture well for Lobelia, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Lobelia root diseases.
DeKalb County Soil Profile
Soil Type
Clay Loam
Soil pH
5.5-6.8
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 DeKalb County
How your county's soil matches Lobelia's growing requirements.
Soil pH
Your soil pH (5.5–6.8) overlaps with Lobelia's range (6.0–7.0), though not a perfect match.
Soil Texture
The clay loam soil in DeKalb County is excellent for Lobelia — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.2%). Annual compost additions will help Lobelia.
How to Plant Lobelia
Succession Planting Lobelia
Sow every 8 weeks. Last sowing by Aug 12 to harvest before frost.
Lobelia Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
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 | — | 4.7" | 0" | ❄️ Dormant |
| Feb | — | 4.1" | 0" | ❄️ Dormant |
| Mar | — | 5.9" | 0" | ❄️ Dormant |
| Apr | 4.3" | 4" | 0.3" | 💧 Light watering |
| May | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 5.8" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 5.8" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 5" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Oct | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Nov | — | 4.6" | 0" | ❄️ Dormant |
| Dec | — | 5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in DeKalb 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 — DeKalb County, AL
Lobelia Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 4 | Feb 4 – Feb 18 |
| Transplant Outdoors | February 25 | Feb 25 – Mar 11 |
| Bloom | April 22 | Apr 22 – Jun 17 |
· 6" apart · Rows 8" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors Transplant Outdoors |
| March | Transplant Outdoors |
| April | Bloom |
| May | Bloom |
| June | Bloom |
| July | — |
| August | — |
| 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 8a
📆 Growing Season
213 days in DeKalb County
Growing Tips for Lobelia in DeKalb County
Direct sow Lobelia outdoors after April 01 in DeKalb County when soil has warmed and frost danger has passed.
With DeKalb County's clay soil (28% clay), work in 3-4 inches of compost before planting Lobelia. Avoid tilling when soil is wet to prevent compaction.
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 DeKalb County, AL?
DeKalb County is in Zone 8a with an average last frost of April 1. Plan your Lobelia planting based on this frost date — see the calendar above for exact timing.
What planting zone is DeKalb County, AL?
DeKalb County, Alabama is in USDA Hardiness Zone 8a. The average last spring frost is April 1 and first fall frost is October 31.
When should I plant Lobelia in DeKalb County County, ?
In DeKalb County County, , plant Lobelia after the last frost (around April 1) and before the first frost (around October 31). Best results when soil holds above 50°F.
What growing zone is DeKalb County County, for Lobelia?
DeKalb County County sits in USDA Zone 8a. Lobelia grows reliably in zones 3a through 9b, so it's a good fit here.
Can Lobelia grow in DeKalb County County's climate?
Yes — Lobelia grows well in DeKalb County County's temperate climate. DeKalb County County averages a 213-day frost-free season, with last frost around April 1 and first frost around October 31.
Your DeKalb County Garden Planner — Free
A 22-page printable planner built for DeKalb County (Zone 8a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.