The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By looking at the USDA zone info for Watertown it's a good idea to figure out when it's possible to plant hypericum.

Planting Calendar for Hypericum

Frost tolerance for hypericum:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

You can plant hypericum a bit earlier in the year because they do ok in moderate cold.

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

The last month that you can plant hypericum and expect a good harvest is probably August. If you wait any later than that and your hypericum may not have a chance to fully mature. If you are starting your hypericum 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 May 15 in Watertown. You should expect an average low temperature of -25°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. Half of the time in Watertown last frost occurs after May 15 so always be ready to cover your hypericum if you have a surprise late frost.

USDA Zone Info for Watertown

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Watertown

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