Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant cauliflower in Portland should be estimated by using the USDA zone info.

Planting Calendar for Cauliflower

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

Since cauliflower do well in moderate cold you can plant them a little bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant cauliflower 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 cauliflower and expect a good harvest is probably September. If you wait any later than that and your cauliflower may not have a chance to fully mature. You can get started a few weeks earlier by starting your cauliflower indoors.

Last Frost Date

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

Always keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Portland and it can change quite a bit from year to year. Half of the time in Portland you get surprised by a frost after April 15 so always be ready to protect your cauliflower 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.