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.

You will be able to determine when it's the best time to plant potatos by checking out the USDA zone info for Portland.

Planting Calendar for Potatos

Frost tolerance for potatos:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

You can plant potatos a lot earlier in the year because they are one of those plants that can tolerate quite a bit of cold weather.

The earliest that you can plant potatos in Portland 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 potatos and expect a good harvest is probably September. You probably don't want to wait any later than that or else your potatos may not have a chance to really do well. You can get started a few weeks earlier by starting your potatos indoors.

Last Frost Date

On average the last frost has passed is on March 15 in Portland. In the coldest months of winter you should expect an average low temperature of 15°F.

It's important to remember that USDA zone info for Portland is an average and the actual date of last frost changes from year to year. Since half of the time in Portland it frosts late in the year after March 15 be ready to protect your potatos in the event of one of those late frosts.

USDA Zone Info for Portland

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 Portland

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