One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Watertown you can estimate when it's the best time to plant coral bells by referring to the USDA zone info.

Planting Calendar for Coral Bells

Frost tolerance for coral bells:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Coral Bells do ok in some cold which tells us that you can plant them a little earlier in the year than more sensitive plants.

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

The last month that you can plant coral bells and expect a good harvest is probably August. You probably don't want to wait any later than that or else your coral bells may not have a chance to really do well. You can get started a few weeks earlier by starting your coral bells indoors.

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 is an average the actual date of last frost will vary from year to year. Half of the time in Watertown last frost occurs after May 15 so make sure that you are prepared to protect your coral bells if you have 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.