One of the first steps you take when you are figuring out your gardening schedule is find your 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 figuring out when it's possible to plant torenia is to refer to the USDA zone info for Watertown.

Planting Calendar for Torenia

Frost tolerance for torenia:	Not tolerant of frost.
When to plant:	After the last frost.

Since torenia require warm weather it is necessary to wait until after the last frost before you can plant them.

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

The last month that you can plant torenia and expect a good harvest is probably August. If you wait any later than that and your torenia may not have a chance to grow to maturity. If you are starting your torenia indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on May 15 in Watertown. You can 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 changes from year to year. Half of the time in Watertown it frosts late in the year after May 15 so just be sure to be ready to protect your torenia in the event of one of those late frosts.

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.