One of the best tools that you have as gardeners to help us figure out 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.

A way of estimating when you can plant hemerocallis is to examine the USDA zone info for Watertown.

Planting Calendar for Hemerocallis

Frost tolerance for hemerocallis:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Hemerocallis are moderately cold tolerant which tells us that you can get them planted earlier than more sensitive plants.

The earliest that you can plant hemerocallis in Watertown is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant hemerocallis and expect a good harvest is probably August. Any later than that and your hemerocallis may not have a chance to fully mature. You can get started a little bit earlier by starting your hemerocallis indoors.

Last Frost Date

The average date of last frost is May 15 in Watertown. In the coldest months of winter you can expect an average low temperature of -30°F.

Keep in mind that USDA zone info for Watertown is just an average and the actual date of last frost changes from year to year. Half of the time in Watertown there is a last frost after May 15 so be sure to be ready to protect your hemerocallis in the event of one of those late frosts.

USDA Zone Info for Watertown

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Watertown

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