One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's a good idea to estimate when you can plant jerusalem artichokes by checking out the USDA zone info for Portland.

Planting Calendar for Jerusalem artichokes

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

Jerusalem artichokes do ok in moderate cold which tells us that you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant jerusalem artichokes 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 jerusalem artichokes and expect a good harvest is probably September. Any later than that and your jerusalem artichokes may not have a chance to fully mature. Starting your jerusalem artichokes indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is March 15 in Portland. You should expect an average low temperature of 15°F in the coldest months of winter.

Since the USDA zone info for Portland may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Portland it frosts late in the year after March 15 so be sure to be ready to cover your jerusalem artichokes in the event of a surprise late frost.

USDA Zone Info for Portland

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Portland

You may be interested in your other planting guides for Portland.