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When to Plant Lobelia in Elko County, NV

Elko County, Nevada Zone 5b June

Your June planting checklist for Elko County, Nevada

We've pulled the most time-sensitive tasks for Elko County, Nevada this June and put them front and centre. Tackle them in order.

Avg. last frost June 5
Avg. first frost September 15
Soil temp (4") 51°F
Watering Critical
Pest pressure High
Daylight 14.9 hrs
Coming up in July — start thinking about
  • First harvests: lobelia

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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.

Elko County, Nevada is in USDA Zone 5b. The average last spring frost is June 5 and the first fall frost is September 15, giving you a growing season of approximately 102 days.

At an elevation of 5,859 feet, Elko County receives approximately 15.1 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 92°F, providing good warmth for Lobelia during the growing season. Sandy soil warms quickly in spring — great for early planting — but Lobelia will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Lobelia successfully. Mulch heavily to conserve soil moisture.

Annual Blooms in Spring Pollinator-friendly
Elko County, NV (Zone 5b) Short season
102 days
Last Spring Frost June 5
102 growing days
First Fall Frost September 15

Elko County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.2-8.5

Drainage

Well Drained

Lobelia Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 17 Transplant: May 19 🌸 Bloom: Jul 14 – Sep 29
Recommended (50%) ✗ May not fit
Start indoors: Mar 27 Transplant: May 29 🌸 Bloom: Jul 24 – Oct 9
Safe Start (90%) ✗ May not fit
Start indoors: Apr 9 Transplant: Jun 11 🌸 Bloom: Aug 6 – Oct 22

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 Elko County

How your county's soil matches Lobelia's growing requirements.

Soil pH

Your soil pH (7.2–8.5) is more alkaline than Lobelia prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Elko County warms quickly in spring but drains fast. Lobelia will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Lobelia.

Organic Matter

Organic matter is low (0.8%). Add 2-3 inches of compost before planting Lobelia.

How to Plant Lobelia

6"
Between Plants
8"
Between Rows

Lobelia Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 739 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — 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" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 0.9" 0" ❄️ Dormant
Apr 0.5" 0" ❄️ Dormant
May 0.3" 0" ❄️ Dormant
Jun 4.3" 0.4" 3.9" 🚿 Regular watering
Jul 4.3" 2.7" 1.6" 💧 Light watering
Aug 4.3" 3.1" 1.2" 💧 Light watering
Sep 4.3" 2" 2.3" 🚿 Regular watering
Oct 1.5" 0" ❄️ Dormant
Nov 0.7" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Elko 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 needs ~1,425 GDD — county provides 1,938 GDD Excellent fit

Lobelia Planting Timeline — Elko County, NV

Lobelia Planting Calendar

Activity When Date Range
Start Indoors March 27 Mar 27 – Apr 10
Transplant Outdoors May 29 May 29 – Jun 12
Bloom July 24 Jul 24 – Oct 9

· 6" apart · Rows 8" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors
May Transplant Outdoors
June Transplant Outdoors
July Bloom
August Bloom
September Bloom
October Bloom
November
December

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

70–80 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5b

📆 Growing Season

102 days in Elko County

Growing Tips for Lobelia in Elko County

Direct sow Lobelia outdoors after June 05 in Elko County when soil has warmed and frost danger has passed.

Sandy soil in Elko County dries quickly — mulch Lobelia with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

Elko County receives only 15" 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 →

Frequently Asked Questions

When should I plant Lobelia in Elko County, NV?

Elko County is in Zone 5b with an average last frost of June 5. Plan your Lobelia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Elko County, NV?

Elko County, Nevada is in USDA Hardiness Zone 5b. The average last spring frost is June 5 and first fall frost is September 15.

🌱

Your Elko County Garden Planner — Free

A 22-page printable planner built for Elko County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Elko County, NV. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.