The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Washington can be looked at to estimate when you can plant nierembergia.

Planting Calendar for Nierembergia

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

Since nierembergia require warm weather you really should wait until after the last frost has passed 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. If you wait any later than that and your nierembergia may not have a chance to really do well. Starting your nierembergia indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Washington the average date of last frost happens on March 15. In the coldest months of winter you should expect an average low temperature of 10°F.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Washington and it can change quite a bit from year to year. Since half of the time in Washington you get surprised by a frost after March 15 be ready to cover your nierembergia if you have a surprise late frost.

USDA Zone Info for Washington

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Washington

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