One of the first steps you take when you are making a decision about 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.

In Spokane you can estimate when it's a good idea to plant sweet potatos by referring to the USDA zone info.

Planting Calendar for Sweet Potatos

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

Sweet Potatos are not cold tolerant which means that it's important to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant sweet potatos in Spokane 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 potatos and expect a good harvest is probably August. Any later than that and your sweet potatos may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your sweet potatos indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Spokane. It might get as low as -5°F during the coldest months of winter.

Keep in mind 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 Spokane and it can change quite a bit from year to year. Half of the time in Spokane it frosts late in the year after April 15 so make sure that you are ready to protect your sweet potatos if you have a surprise late frost.

USDA Zone Info for Spokane

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Spokane

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