When to plant Lobelia in Stevens County, MN
Plant Lobelia in Stevens County, between May 2 and May 16 — the only viable window. Zone 4b's short season (157 frost-free days) rules out a fall crop.
When to Plant Lobelia in Stevens County, MN
This month in Stevens County, Minnesota
Each item below is timed to Stevens County, Minnesota's frost dates and soil temperatures. Skip nothing, stress about nothing.
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Harvest lobelia as they ripen
The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.
July will be here before you know it — start on
- Starting indoors: lobelia
- 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.
Stevens County, Minnesota is in USDA Zone 4b. The average last spring frost is May 2 and the first fall frost is October 6, giving you a growing season of approximately 157 days.
At an elevation of 1,259 feet, Stevens County receives approximately 37.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Lobelia to ensure they mature before fall.
Stevens County 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 Stevens County
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 Stevens County is excellent for Lobelia — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.0%) — Lobelia will thrive.
How to Plant Lobelia
Succession Planting Lobelia
Sow every 8 weeks. Last sowing by Jul 18 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 | — | 1.7" | 0" | ❄️ Dormant |
| Feb | — | 1.6" | 0" | ❄️ Dormant |
| Mar | — | 2.6" | 0" | ❄️ Dormant |
| Apr | — | 4.1" | 0" | ❄️ Dormant |
| May | 4.3" | 4.7" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 4.9" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Aug | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Sep | 4.3" | 2.9" | 1.4" | 💧 Light watering |
| Oct | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| Nov | — | 2.8" | 0" | ❄️ Dormant |
| Dec | — | 2.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Stevens 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 — Stevens County, MN
Lobelia Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 21 | Feb 21 – Mar 7 |
| Transplant Outdoors | May 2 | May 2 – May 16 |
| Bloom | June 27 | Jun 27 – Aug 29 |
· 6" apart · Rows 8" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors |
| April | — |
| May | Transplant Outdoors |
| 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 4b
📆 Growing Season
157 days in Stevens County
Growing Tips for Lobelia in Stevens County
Direct sow Lobelia outdoors after May 02 in Stevens 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 Stevens County, MN?
Stevens County is in Zone 4b with an average last frost of May 2. Plan your Lobelia planting based on this frost date — see the calendar above for exact timing.
What planting zone is Stevens County, MN?
Stevens County, Minnesota is in USDA Hardiness Zone 4b. The average last spring frost is May 2 and first fall frost is October 6.
When should I plant Lobelia in Stevens County, MN?
In Stevens County, MN, plant Lobelia after the last frost (around May 2) and before the first frost (around October 6). Best results when soil holds above 50°F.
What growing zone is Stevens County, MN for Lobelia?
Stevens County sits in USDA Zone 4b. Lobelia grows reliably in zones 3a through 9b, so it's a good fit here.
Can Lobelia grow in Stevens County's climate?
Yes — Lobelia grows well in Stevens County's temperate climate. Stevens County averages a 157-day frost-free season, with last frost around May 2 and first frost around October 6.
Your Stevens County Garden Planner — Free
A 22-page printable planner built for Stevens County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.