One of the first steps you take when you are making a decision about 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.

The USDA zone info for Pullman can be looked at to figure out when you can plant liatris.

Planting Calendar for Liatris

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

Liatris do ok in pretty solid cold which means that you can plant them earlier in the year than more sensitive plants.

The earliest that you can plant liatris in Pullman 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 liatris and expect a good harvest is probably September. 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 Pullman the average date of last frost happens on April 15. You should expect an average low temperature of -5°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Pullman is just an average and the actual date of last frost changes from year to year. Since half of the time in Pullman there is a last frost after April 15 be ready to protect your liatris if you have a surprise late frost.

USDA Zone Info for Pullman

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°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 0°F.

Plants to Grow in Pullman

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