One of the first steps you take when you are determining 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.

In Seattle you can figure out when it's a good idea to plant bougainvillea by reviewing the USDA zone info.

Planting Calendar for Bougainvillea

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

Since bougainvillea do not do well in cold weather it's necessary to wait until after the last frost has passed before you can plant them.

The earliest that you can plant bougainvillea in Seattle 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 fully mature. Starting your bougainvillea indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on March 15 in Seattle. In the coldest months of winter you can expect an average low temperature of 15°F.

Since the USDA zone info for Seattle is an average the actual date of last frost changes from year to year. Half of the time in Seattle there is a last frost after March 15 so make sure that you are ready to cover your bougainvillea if you have one of those late frosts.

USDA Zone Info for Seattle

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

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

Plants to Grow in Seattle

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