One of the first steps you take when you are estimating your gardening schedule is find your 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.

The first chance to plant trachelium in Seattle should be determined by using the USDA zone info.

Planting Calendar for Trachelium

Frost tolerance for trachelium:	Not tolerant of frost.
When to plant:	After the last frost.

It's probably not a good idea to plant trachelium until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant trachelium 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 trachelium and expect a good harvest is probably August. If you wait any later than that and your trachelium may not have a chance to really do well. Starting your trachelium indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is March 15 in Seattle. In the coldest months of winter you can expect an average low temperature of 15°F.

Since the USDA zone info for Seattle is not always accurate 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 protect your trachelium in the event of one of those late frosts.

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.