The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The earliest that you can plant kohlrabi in Portland should be estimated by referring to the USDA zone info.

Planting Calendar for Kohlrabi

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

Since kohlrabi are one of those plants that can tolerate a little bit of cold weather you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant kohlrabi 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 kohlrabi and expect a good harvest is probably September. If you wait any later than that and your kohlrabi may not have a chance to fully mature. Starting your kohlrabi indoors is a great way to get them started a few 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. Half of the time in Portland there is a last frost after April 15 so make sure that you are ready to protect your kohlrabi 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.