Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of determining when it's a good idea to plant schizanthus is to consult the USDA zone info for Watertown.

Planting Calendar for Schizanthus

Frost tolerance for schizanthus:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Schizanthus require warm weather which tells us that you need to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant schizanthus 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 schizanthus and expect a good harvest is probably August. If you wait any later than that and your schizanthus may not have a chance to fully mature. If you are starting your schizanthus 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. In the coldest months of winter you should expect an average low temperature of -30°F.

Since the USDA zone info for Watertown is an average the actual date of last frost is different every year. Half of the time in Watertown you get a frost after May 15 so make sure that you are ready to protect your schizanthus in the event of a late frost.

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.