When to Plant Lobelia in USDA Zone 8a
Your June planting checklist for Zone 8a
June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Zone 8a.
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Basket week: lobelia
This is the payoff month. Bring a basket, bring a friend, and get into the beds.
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.
In Zone 8a, the average last spring frost is around March 8 and the first fall frost is around November 18, giving you a growing season of approximately 255 days.
Lobelia Planting Timeline — Zone 8a
Where Is USDA Zone 8a?
The map below highlights the states that contain Zone 8a. Click any state to see the Lobelia planting schedule for that location.
Lobelia Planting Calendar — Zone 8a
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 11 | Jan 11 – Jan 25 |
| Transplant Outdoors | February 1 | Feb 1 – Feb 15 |
| Bloom | March 29 | Mar 29 – May 24 |
· 6" apart · Rows 8" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Transplant Outdoors |
| March | Bloom |
| April | Bloom |
| May | Bloom |
| June | — |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Free Zone 8a Planting Calendar PDF
Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 8a with start dates, transplant windows, and harvest times.
Growing Conditions
Sun
Partial Shade (3-6 hours)
💧 Water
Moderate — regular watering
Days to Maturity
70–80 days
Soil pH
6 – 7
Zone Temperature Range
10°F to 15°F average annual minimum
Growing Season
255 days (Zone 8a average)
Planting Specifications
| Plant Spacing | 6 inches apart |
| Row Spacing | 8 inches between rows |
Succession Planting Lobelia in Zone 8a
Sow every 8 weeks for continuous harvest throughout the season.
Growing Tips for Lobelia in Zone 8a
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
The Gardener's Encyclopedia to Companion Planting
The pairings that make vegetables, herbs, and flowers grow better — and the ones that quietly wreck a bed.
- Proven pairings for 200+ vegetables, herbs, flowers, and fruits
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Saving Lobelia Seeds
Recommended for Your Garden
Start seeds indoors with reusable cell trays and humidity domes.
Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.
Keep your garden organized with durable, weather-resistant plant labels.
Related Plants
Lobelia in Other Zones
Lobelia by State
- Alabama
- Alaska
- Arizona
- Arkansas
- California
- Colorado
- Connecticut
- Delaware
- Florida
- Georgia
- Hawaii
- Idaho
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Maine
- Maryland
- Massachusetts
- Michigan
- Minnesota
- Mississippi
- Missouri
- Montana
- Nebraska
- Nevada
- New Hampshire
- New Jersey
- New Mexico
- New York
- North Carolina
- North Dakota
- Ohio
- Oklahoma
- Oregon
- Pennsylvania
- Rhode Island
- South Carolina
- South Dakota
- Tennessee
- Texas
- Utah
- Vermont
- Virginia
- Washington
- West Virginia
- Wisconsin
- Wyoming
Frequently Asked Questions
When should I plant Lobelia in Zone 8a?
In Zone 8a, plan your Lobelia planting around the average last frost date of March 8. Start seeds indoors around January 11. Transplant seedlings around February 1.
Can Lobelia grow in Zone 8a?
Yes, Lobelia can grow well in Zone 8a, hardy in USDA zones 3a through 9b. Zone 8a has a growing season of approximately 255 days, which is sufficient for Lobelia (70-80 days to maturity).
When can I harvest Lobelia in Zone 8a?
In Zone 8a, expect to harvest Lobelia from March 29 – May 24. Lobelia takes 70-80 days from planting to harvest.
What is the last frost date for Zone 8a?
The average last spring frost in Zone 8a is around March 8, and the first fall frost is around November 18. This gives a growing season of approximately 255 days. These are 50% probability dates — actual frost dates vary year to year.
What should I plant next to Lobelia?
Good companion plants for Lobelia include Petunias, Sweet Alyssum, Begonias, Impatiens. These companions can help with pest control, pollination, and nutrient sharing.
Your Zone 8a Garden Planner — Free
A 22-page printable planner tailored to Zone 8a. Planting dates, monthly task lists, harvest log, seed inventory, and succession charts — everything you need to plan a full season.