One of the best tools that you have as gardeners to help us figure out your gardening schedule is the 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 first chance to plant tomatos in Portland should be estimated by referring to the USDA zone info.

Planting Calendar for Tomatos

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

Since tomatos require warm weather it is necessary to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant tomatos 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 tomatos and expect a good harvest is probably August. Any later than that and your tomatos may not have a chance to fully mature. You can get started a few weeks earlier by starting your tomatos indoors.

Last Frost Date

The average date of last frost is April 15 in Portland. You should expect an average low temperature of -15°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Portland is an average and the actual date of last frost is different every year. Since half of the time in Portland you get a frost after April 15 be ready to protect your tomatos in the event of a surprise late frost.

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.