The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The best time to plant liatris in Prosser should be estimated by reviewing 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 a lot earlier in the year than other plants that might not handle the cold.

The earliest that you can plant liatris in Prosser 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. You probably don't want to wait any later than that or else your liatris may not have a chance to fully mature. If you are starting your liatris indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Prosser the average date of last frost happens on April 15. You should expect an average low temperature of 0°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Prosser is just an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Prosser last frost occurs after April 15 so always be ready to protect your liatris in the event of one of those late frosts.

USDA Zone Info for Prosser

Here is the info for USDA Zone 7a.

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

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Prosser

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