One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Mill Creek you can determine when to plant liatris 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 do well in cold you can plant them much earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant liatris in Mill Creek 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. If you are starting your liatris indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is March 15 in Mill Creek. It might get as low as 15°F during the coldest months of winter.

Since the USDA zone info for Mill Creek is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Mill Creek last frost occurs after March 15 be ready to protect your liatris in the event of a surprise late frost.

USDA Zone Info for Mill Creek

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in Mill Creek

You may be interested in your other planting guides for Mill Creek.