One of the first steps you take when you are determining 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.

A common way of figuring out when it's the best time to plant sweet potatos is to examine the USDA zone info for Gresham.

Planting Calendar for Sweet Potatos

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

Since sweet potatos do not do well in cold weather it's important to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant sweet potatos in Gresham 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. Starting your sweet potatos indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Gresham the average date of last frost happens on March 15. In the coldest months of winter you should expect an average low temperature of 15°F.

Since the USDA zone info for Gresham is not always accurate the actual date of last frost changes from year to year. Since half of the time in Gresham it frosts late in the year after March 15 be ready to protect your sweet potatos if you have a surprise late frost.

USDA Zone Info for Gresham

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 Gresham

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