One of the first steps you take when you are figuring out 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 earliest that you can plant sweet potato vine in Washington can be determined by checking out the USDA zone info.

Planting Calendar for Sweet Potato Vine

Frost tolerance for sweet potato vine:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Sweet Potato Vine do not do well in cold weather which tells us that you really should wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant sweet potato vine in Washington 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 sweet potato vine and expect a good harvest is probably August. You probably don't want to wait any later than that or else your sweet potato vine may not have a chance to really do well. If you are starting your sweet potato vine indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

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

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Washington and it is different every year. Since half of the time in Washington last frost occurs after April 15 be ready to protect your sweet potato vine if you have one of those late frosts.

USDA Zone Info for Washington

Here is the info for USDA Zone 5b.

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

Plants to Grow in Washington

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