Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's possible to determine when you can plant lobelia by checking out the USDA zone info for Harrisburg.

Planting Calendar for Lobelia

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

Since lobelia do well in cold you can plant them much earlier in the year than more sensitive plants.

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 fully mature. 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. In the coldest months of winter you can expect an average low temperature of 5°F.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Harrisburg and it changes from year to year. Half of the time in Harrisburg you get a frost after April 15 so make sure that you are ready to cover your lobelia if you have a late frost.

USDA Zone Info for Harrisburg

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Harrisburg

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