Before planting it is a good idea to find your USDA Zone info to estimate your garden 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 possible to determine when it's the best time to plant vinca vine by looking at the USDA zone info for Seattle.

Planting Calendar for Vinca Vine

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

Vinca Vine are one of those plants that can tolerate a little bit of cold weather which tells us that you can get them planted earlier than other frost tender plants.

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

Last Frost Date

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

Since the USDA zone info for Seattle may not be accurate from year to year 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 protect your vinca vine in the event of 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.