The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's a good idea to figure out when it's the best time to plant dahlias by looking at the USDA zone info for Seattle.

Planting Calendar for Dahlias

Frost tolerance for dahlias:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Dahlias do not do well in cold weather which means that it is necessary to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant dahlias in Seattle 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 dahlias and expect a good harvest is probably August. Any later than that and your dahlias may not have a chance to fully mature. If you are starting your dahlias indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Seattle the average date of last frost happens on March 15. You can expect an average low temperature of 15°F in the coldest months of winter.

It's important to remember that USDA zone info for Seattle may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Since half of the time in Seattle it frosts late in the year after March 15 be ready to cover your dahlias if you have a 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.