One of the first steps you take when you are determining 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 estimate when to plant lobelia by reviewing the USDA zone info for Duluth.

Planting Calendar for Lobelia

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

Since lobelia are one of those plants that can tolerate quite a bit of cold weather you can plant them quite a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant lobelia in Duluth 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. You probably don't want to wait any later than that or else your lobelia may not have a chance to fully mature. You can get started a few weeks earlier by starting your lobelia indoors.

Last Frost Date

The average date of last frost is April 15 in Duluth. You can expect an average low temperature of 5°F in the coldest months of winter.

It's important to remember that USDA zone info for Duluth is not always accurate and the actual date of last frost changes from year to year. Half of the time in Duluth there is a last 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 Duluth

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 Duluth

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