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.

It's a good idea to figure out when to plant xerianthemum by reviewing the USDA zone info for Seattle.

Planting Calendar for Xerianthemum

Frost tolerance for xerianthemum:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Xerianthemum do ok in moderate cold which tells us that you can plant them slightly earlier than other plants that might not handle the cold.

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

The last month that you can plant xerianthemum and expect a good harvest is probably August. Any later than that and your xerianthemum may not have a chance to really do well. If you are starting your xerianthemum indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on March 15 in Seattle. It might get as low as 15°F during the coldest months of winter.

Since the USDA zone info for Seattle is just an average the actual date of last frost changes from year to year. Since half of the time in Seattle you get a frost after March 15 be ready to cover your xerianthemum if you have a surprise late frost.

USDA Zone Info for Seattle

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Seattle

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