One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By reviewing the USDA zone info for Harrisburg it's a good idea to determine when it's a good idea to plant lobelia.

Planting Calendar for Lobelia

Frost tolerance for lobelia:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Lobelia are one of those plants that can tolerate quite a bit of cold weather which means that you can get them planted much earlier than other plants that might not handle the cold.

The earliest that you can plant lobelia in Harrisburg is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant lobelia and expect a good harvest is probably September. Any later than that and your lobelia may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your lobelia indoors.

Last Frost Date

The average date of last frost is April 15 in Harrisburg. It might get as low as 0°F during the coldest months of winter.

Since the USDA zone info for Harrisburg is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Harrisburg there is a last frost after April 15 be ready to cover your lobelia if you have a late frost.

USDA Zone Info for Harrisburg

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Harrisburg

You may be interested in your other planting guides for Harrisburg.