The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Portland you can estimate when it's the best time to plant lettuce by checking out the USDA zone info.

Planting Calendar for Lettuce

Frost tolerance for lettuce:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since lettuce are one of those plants that can tolerate a little bit of cold weather you can plant them a little bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant lettuce 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 lettuce and expect a good harvest is probably September. If you wait any later than that and your lettuce may not have a chance to fully mature. If you are starting your lettuce indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

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

Just be sure to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Portland and it can change quite a bit from year to year. Since half of the time in Portland there is a last frost after April 15 be ready to cover your lettuce if you have a 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.