One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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.

By referring to the USDA zone info for Portland it's a good idea to estimate when it's the best time to plant brussels sprouts.

Planting Calendar for Brussels Sprouts

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

Brussels Sprouts do ok in mild cold which means that you can plant them a little earlier in the year than other frost tender plants.

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

Last Frost Date

In Portland the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Portland is just an average the actual date of last frost is different every year. Since half of the time in Portland there is a last frost after April 15 be ready to cover your brussels sprouts 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.