When to Plant Lobelia in Millard County, UT
What to do in August
We've pulled the most time-sensitive tasks for Millard County, Utah this August and put them front and centre. Tackle them in order.
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Bring in the lobelia
This is the payoff month. Bring a basket, bring a friend, and get into the beds.
Coming up in September — start thinking about
- 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.
Millard County, Utah is in USDA Zone 6a. The average last spring frost is May 16 and the first fall frost is September 30, giving you a growing season of approximately 137 days.
At an elevation of 6,525 feet, Millard County receives approximately 24 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Lobelia to ensure they mature before fall.
Millard County Soil Profile
Soil Type
Loam
Soil pH
6.5-8
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 Millard County
How your county's soil matches Lobelia's growing requirements.
Soil pH
Your soil pH (6.5–8.0) is more alkaline than Lobelia prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Millard County is excellent for Lobelia — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.3%). Annual compost additions will help Lobelia.
How to Plant Lobelia
Succession Planting Lobelia
Sow every 8 weeks. Last sowing by Jul 12 to harvest before frost.
Lobelia Water Budget
Water stress score is 8/10 — 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 | — | 1.8" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2" | 0" | ❄️ Dormant |
| Apr | — | 2.7" | 0" | ❄️ Dormant |
| May | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| Jun | 4.3" | 1.7" | 2.6" | 🚿 Regular watering |
| Jul | 4.3" | 2.1" | 2.2" | 🚿 Regular watering |
| Aug | 4.3" | 2.2" | 2.1" | 💧 Light watering |
| Sep | 4.3" | 2" | 2.3" | 🚿 Regular watering |
| Oct | — | 2.2" | 0" | ❄️ Dormant |
| Nov | — | 1.6" | 0" | ❄️ Dormant |
| Dec | — | 1.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Millard 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 — Millard County, UT
Lobelia Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 14 | Mar 14 – Mar 28 |
| Transplant Outdoors | May 2 | May 2 – May 16 |
| Bloom | June 27 | Jun 27 – Sep 19 |
· 6" apart · Rows 8" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | — |
| 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 · 1-2 times/week
📅 Days to Maturity
70–80 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 6a
📆 Growing Season
137 days in Millard County
Growing Tips for Lobelia in Millard County
Direct sow Lobelia outdoors after May 16 in Millard County when soil has warmed and frost danger has passed.
Millard County receives only 24" of rain annually. Lobelia needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
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 Millard County, UT?
Millard County is in Zone 6a with an average last frost of May 16. Plan your Lobelia planting based on this frost date — see the calendar above for exact timing.
What planting zone is Millard County, UT?
Millard County, Utah is in USDA Hardiness Zone 6a. The average last spring frost is May 16 and first fall frost is September 30.
Your Millard County Garden Planner — Free
A 22-page printable planner built for Millard 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.