One of the first steps you take when you are getting a good idea 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.

You should be able to determine when it's a good idea to plant lobelia by reviewing the USDA zone info for Joliet.

Planting Calendar for Lobelia

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

Lobelia do well in cold which means that you can start planting them much earlier than other plants that might not handle the cold.

The earliest that you can plant lobelia in Joliet 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. If you wait any later than that and your lobelia may not have a chance to fully mature. If you are starting your lobelia indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Joliet. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Joliet may not be accurate from year to year the actual date of last frost changes from year to year. Half of the time in Joliet you get surprised by a frost after April 15 so just be sure to be ready to protect your lobelia in the event of one of those late frosts.

USDA Zone Info for Joliet

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Joliet

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