Before planting it is a good idea to find your USDA Zone info to determine your garden 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 Downingtown you should be able to estimate when 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.

Since liatris are very cold tolerant you can plant them much earlier in the year than more sensitive plants.

The earliest that you can plant liatris in Downingtown 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 fully mature. You can get started a little bit earlier by starting your liatris indoors.

Last Frost Date

The average date of last frost is April 15 in Downingtown. You should expect an average low temperature of -5°F in the coldest months of winter.

Since the USDA zone info for Downingtown may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in Downingtown last frost occurs after April 15 so be sure to be ready to cover your liatris if you have a late frost.

USDA Zone Info for Downingtown

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 Downingtown

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