The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. 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 read to figure out when it's possible to plant bougainvillea.

Planting Calendar for Bougainvillea

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

Bougainvillea require warm weather which means that it's necessary to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant bougainvillea 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 bougainvillea and expect a good harvest is probably August. You probably don't want to wait any later than that or else your bougainvillea may not have a chance to grow to maturity. You can get started a little bit earlier by starting your bougainvillea indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Watertown. You should expect an average low temperature of -20°F in the coldest months of winter.

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. Since half of the time in Watertown last frost occurs after April 15 be ready to cover your bougainvillea if you have one of those late frosts.

USDA Zone Info for Watertown

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Watertown

You may be interested in your other planting guides for Watertown.