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

The best time to plant calibrachoa in Watertown should be figured out by looking at the USDA zone info.

Planting Calendar for Calibrachoa

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

Calibrachoa are barely cold tolerant which means that you can start planting them slightly earlier than plants that are more sensitive to the cold.

The earliest that you can plant calibrachoa 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 calibrachoa and expect a good harvest is probably August. Any later than that and your calibrachoa may not have a chance to really do well. If you are starting your calibrachoa indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Watertown the average date of last frost happens on May 15. It might get as low as -25°F during the coldest months of winter.

Remember that USDA zone info for Watertown is an average and the actual date of last frost is different every year. Half of the time in Watertown it frosts late in the year after May 15 so make sure that you are ready to protect your calibrachoa if you have 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.