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 alyssum in Washington by looking at the USDA zone info.

Planting Calendar for Alyssum

Frost tolerance for alyssum:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Alyssum do well in a bit of cold which tells us that you can plant them earlier in the year than other plants that might not handle the cold.

The earliest that you can plant alyssum 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 alyssum and expect a good harvest is probably September. Any later than that and your alyssum may not have a chance to grow to maturity. Starting your alyssum indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Washington. You can expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for Washington is just an average the actual date of last frost will vary from year to year. Half of the time in Washington it frosts late in the year after April 15 so be sure to be ready to cover your alyssum if you have one of those late frosts.

USDA Zone Info for Washington

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°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 -5°F.

Plants to Grow in Washington

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