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.

The USDA zone info for Washington should be reviewed to determine when you can plant begonias.

Planting Calendar for Begonias

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

Begonias do not do well in cold weather which tells us that it is necessary to wait until it warms up after the last frost before you can plant them.

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

Last Frost Date

The average date of last frost is April 15 in Washington. In the coldest months of winter you can expect an average low temperature of -15°F.

Always keep in mind that USDA zone info for Washington is just an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Washington there is a last frost after April 15 be ready to cover your begonias in the event of a late frost.

USDA Zone Info for Washington

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°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 -10°F.

Plants to Grow in Washington

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