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 best time to plant impatiens in Washington can be figured out by referring to the USDA zone info.

Planting Calendar for Impatiens

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

It's not a good idea to plant impatiens until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant impatiens 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 impatiens and expect a good harvest is probably August. If you wait any later than that and your impatiens may not have a chance to really do well. Starting your impatiens indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for Washington is just an average the actual date of last frost changes from year to year. Half of the time in Washington you get a frost after April 15 so make sure that you are prepared to protect your impatiens if you have 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.