One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant lisianthus in Petersburg should be figured out by reviewing the USDA zone info.

Planting Calendar for Lisianthus

Frost tolerance for lisianthus:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

It's not a good idea to plant lisianthus until after the last frost because they do not do well in cold weather.

The earliest that you can plant lisianthus in Petersburg is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant lisianthus and expect a good harvest is probably August. Any later than that and your lisianthus may not have a chance to really do well. Starting your lisianthus indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Petersburg the average date of last frost happens on April 15. It might get as low as 5°F during the coldest months of winter.

Always keep in mind that USDA zone info for Petersburg is an average and the actual date of last frost is different every year. Half of the time in Petersburg it frosts late in the year after April 15 so make sure that you are ready to protect your lisianthus if you have a surprise late frost.

USDA Zone Info for Petersburg

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 Petersburg

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