Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can figure out when you can plant nierembergia in Washington by referring to the USDA zone info.

Planting Calendar for Nierembergia

Frost tolerance for nierembergia:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Nierembergia do not do well in cold weather which tells us that you must wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant nierembergia 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 nierembergia and expect a good harvest is probably August. You probably don't want to wait any later than that or else your nierembergia may not have a chance to fully mature. You can get started a few weeks earlier by starting your nierembergia indoors.

Last Frost Date

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

Since the USDA zone info for Washington may not be accurate from year to year the actual date of last frost is different every year. Half of the time in Washington you get a frost after April 15 so make sure that you are prepared to cover your nierembergia in the event of one of those late frosts.

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.