One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can determine when you can plant iberis in Washington by checking out the USDA zone info.

Planting Calendar for Iberis

Frost tolerance for iberis:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since iberis are moderately cold tolerant you can plant them a little bit earlier in the year than other frost tender plants.

The earliest that you can plant iberis in Washington is February. However, you really should wait until March if you don't want to take any chances.

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

Last Frost Date

On average the last frost is on April 15 in Washington. You should expect an average low temperature of -15°F in the coldest months of winter.

Keep in mind that USDA zone info for Washington may not be accurate from year to year and the actual date of last frost changes from year to year. Since half of the time in Washington you get a frost after April 15 be ready to cover your iberis 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.