Blog

When to Plant Lobelia in Maryland

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.

Maryland spans USDA hardiness zones 6a, 7a, 7b, 8a (with planting data available), so planting dates vary by your location within the state. Click your zone below for the most accurate dates.

Find Your County

Click your county for exact Lobelia planting dates based on your local frost dates.

Hover over a county to see details. Click to view planting guide.

Lobelia Planting Calendar for Maryland

Zone 6a ~193 day growing season · Full guide →

Last frost: April 10 · First frost: October 20 · 193 day season

Activity When Date Range
Start Indoors February 6 Feb 6 – Feb 20
Transplant Outdoors March 27 Mar 27 – Apr 10
Bloom May 22 May 22 – Aug 14
Zone 7a ~221 day growing season · Full guide →

Last frost: March 25 · First frost: November 1 · 221 day season

Activity When Date Range
Start Indoors January 21 Jan 21 – Feb 4
Transplant Outdoors March 4 Mar 4 – Mar 18
Bloom April 29 Apr 29 – Jul 22
Zone 7b ~235 day growing season · Full guide →

Last frost: March 18 · First frost: November 8 · 235 day season

Activity When Date Range
Start Indoors January 14 Jan 14 – Jan 28
Transplant Outdoors February 18 Feb 18 – Mar 4
Bloom April 15 Apr 15 – Jun 24
Zone 8a ~255 day growing season · Full guide →

Last frost: March 8 · First frost: November 18 · 255 day season

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

Growing Tips for Maryland

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.

Frequently Asked Questions

When should I plant Lobelia in Maryland?

Planting dates for Lobelia in Maryland depend on your USDA zone. Maryland spans zones 6a, 7a, 7b, 8a. Check the planting calendar above for your specific zone's frost dates and planting windows.

What zone is Maryland for planting?

Maryland contains USDA hardiness zones 6a, 7a, 7b, 8a. Your specific zone depends on your location within the state — northern and higher-elevation areas are in colder zones, while southern and coastal areas are warmer.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals, University Cooperative Extension planting guides. Last updated: June 2026.