One of the first steps you take when you are figuring out 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.

In Portland you can figure out when to plant flowering maple by referring to the USDA zone info.

Planting Calendar for Flowering Maple

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

You really shouldn't plant flowering maple until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant flowering maple 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 flowering maple and expect a good harvest is probably August. You probably don't want to wait any later than that or else your flowering maple may not have a chance to grow to maturity. If you are starting your flowering maple indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Portland. You can 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 just an average because it is based on the USDA zone info for Portland and it will vary from year to year. Since half of the time in Portland it frosts late in the year after April 15 be ready to protect your flowering maple if you have 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.