Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first opportunity to plant liatris in Medical Lake should be determined by using the USDA zone info.

Planting Calendar for Liatris

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

Since liatris are very cold tolerant you can plant them much earlier in the year than other frost tender plants.

The earliest that you can plant liatris in Medical Lake 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. Any later than that and your liatris may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your liatris indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Medical Lake. It might get as low as -10°F during the coldest months of winter.

Keep in mind that USDA zone info for Medical Lake is an average and the actual date of last frost changes from year to year. Since half of the time in Medical Lake last frost occurs after April 15 be ready to protect your liatris if you have one of those late frosts.

USDA Zone Info for Medical Lake

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Medical Lake

You may be interested in your other planting guides for Medical Lake.