The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of making a decision about when it's a good idea to plant cauliflower is to use the USDA zone info for Portland.

Planting Calendar for Cauliflower

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

Cauliflower do well in a little bit of cold which means that you can plant them just a bit earlier in the year than other frost tender plants.

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. You probably don't want to wait any later than that or else your cauliflower may not have a chance to grow to maturity. Starting your cauliflower indoors is a great way to get them started a couple of 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.

Keep in mind that the actual date of last frost is 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 make sure that you are prepared to protect your cauliflower 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.