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 can determine when it's the best time to plant flax in Portland by checking out the USDA zone info.

Planting Calendar for Flax

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

Flax do well in moderate cold which means that you can plant them earlier than other plants that might not handle the cold.

The earliest that you can plant flax 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 flax and expect a good harvest is probably September. You probably don't want to wait any later than that or else your flax may not have a chance to really do well. If you are starting your flax indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost has passed is on 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 the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Portland and it changes from year to year. Since half of the time in Portland last frost occurs after April 15 be ready to cover your flax 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.