One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant asparagus lettuce in Portland can be determined by referring to the USDA zone info.

Planting Calendar for Asparagus lettuce

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

Asparagus lettuce do not do well in cold weather which tells us that you need to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant asparagus lettuce in Portland is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant asparagus lettuce and expect a good harvest is probably September. You probably don't want to wait any later than that or else your asparagus lettuce may not have a chance to grow to maturity. You can get started a little bit earlier by starting your asparagus lettuce indoors.

Last Frost Date

In Portland the average date of last frost happens on February 15. In the coldest months of winter you should expect an average low temperature of 25°F.

Keep in mind that USDA zone info for Portland may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in Portland it frosts late in the year after February 15 so make sure that you are prepared to protect your asparagus lettuce in the event of a late frost.

USDA Zone Info for Portland

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Portland

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