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.

The USDA zone info for Watertown can be reviewed to figure out when it's a good idea to plant tithonia.

Planting Calendar for Tithonia

Frost tolerance for tithonia:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Since tithonia are not cold tolerant it's necessary to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant tithonia 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 tithonia and expect a good harvest is probably August. Any later than that and your tithonia may not have a chance to fully mature. You can get started a few weeks earlier by starting your tithonia indoors.

Last Frost Date

On average the last frost is on May 15 in Watertown. In the coldest months of winter you can expect an average low temperature of -25°F.

Since the USDA zone info for Watertown is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Watertown you get surprised by a frost after May 15 so make sure that you are ready to protect your tithonia in the event of a 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.