Before planting it is a good idea to find your USDA Zone info to figure out 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.

The first chance to plant sweet potato vine in Portland should be determined by looking at the USDA zone info.

Planting Calendar for Sweet Potato Vine

Frost tolerance for sweet potato vine:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

It's probably not a good idea to plant sweet potato vine until after the last frost when the weather gets warmer because they require warm weather.

The earliest that you can plant sweet potato vine in Portland 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. If you wait any later than that and your sweet potato vine may not have a chance to fully mature. If you are starting your sweet potato vine indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

It's important to remember that USDA zone info for Portland is just an average and the actual date of last frost changes from year to year. Half of the time in Portland you get a frost after April 15 so just be sure to be ready to cover your sweet potato vine if you have one of those late frosts.

USDA Zone Info for Portland

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 Portland

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