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 reviewing the USDA zone info for Tomah it's a good idea to determine when it's a good idea to plant liatris.

Planting Calendar for Liatris

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

You can plant liatris a lot earlier in the year because they are very cold tolerant.

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

The last month that you can plant liatris and expect a good harvest is probably August. If you wait any later than that and your liatris may not have a chance to grow to maturity. If you are starting your liatris indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Tomah the average date of last frost happens on May 15. You should expect an average low temperature of -25°F in the coldest months of winter.

Remember that USDA zone info for Tomah is an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Tomah last frost occurs after May 15 be ready to cover your liatris if you have 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.