The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By referring to the USDA zone info for Tomah it's a good idea to figure out when to plant lisianthus.

Planting Calendar for Lisianthus

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

Lisianthus are not cold tolerant which means that you have to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant lisianthus in Tomah is May. However, you really should wait until June 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 grow to maturity. You can get started a few weeks earlier by starting your lisianthus indoors.

Last Frost Date

The average date of last frost is May 15 in Tomah. You can expect an average low temperature of -25°F in the coldest months of winter.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Tomah and it can change quite a bit from year to year. Half of the time in Tomah there is a last frost after May 15 so make sure that you are prepared to protect your lisianthus in the event of a surprise late frost.

USDA Zone Info for Tomah

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Tomah

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