One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By using the USDA zone info for Watertown you will be able to determine when it's possible 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.

Liatris are one of those plants that can tolerate quite a bit of cold weather which tells us that you can plant them much earlier than plants that are more sensitive to the cold.

The earliest that you can plant liatris in Watertown 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 little bit earlier by starting your liatris indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Watertown. You can expect an average low temperature of -20°F in the coldest months of winter.

Since the USDA zone info for Watertown may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in Watertown you get surprised by a frost after April 15 be ready to cover your liatris in the event of a late frost.

USDA Zone Info for Watertown

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

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

Plants to Grow in Watertown

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