Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You should be able to estimate when it's possible to plant balsam by looking at the USDA zone info for Portland.

Planting Calendar for Balsam

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

Since balsam require warm weather you really should wait until after the last frost has passed before you can plant them.

The earliest that you can plant balsam 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 balsam and expect a good harvest is probably August. Any later than that and your balsam may not have a chance to really do well. If you are starting your balsam indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Since the USDA zone info for Portland is not always accurate the actual date of last frost is different every year. Half of the time in Portland it frosts late in the year after April 15 so make sure that you are prepared to cover your balsam if you have one of those late frosts.

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.