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.

By reviewing the USDA zone info for Portland it's a good idea to determine when to plant garden mums.

Planting Calendar for Garden Mums

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

Garden Mums do well in moderate cold which means that you can get them planted earlier than more sensitive plants.

The earliest that you can plant garden mums 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 garden mums and expect a good harvest is probably September. If you wait any later than that and your garden mums may not have a chance to grow to maturity. Starting your garden mums indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Portland. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Portland is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Portland you get surprised by a frost after April 15 be ready to protect your garden mums in the event of 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.