One of the first steps you take when you are figuring out your gardening schedule is find your 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 possible to estimate when it's possible to plant garden cress by looking at the USDA zone info for Portland.

Planting Calendar for Garden cress

Frost tolerance for garden cress:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since garden cress do not do well in cold weather it's necessary to wait until after the last frost before you can plant them.

The earliest that you can plant garden cress in Portland is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant garden cress and expect a good harvest is probably September. Any later than that and your garden cress may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your garden cress indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in Portland. You can expect an average low temperature of 25°F in the coldest months of winter.

Keep in mind that USDA zone info for Portland may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in Portland it frosts late in the year after February 15 so be sure to be ready to cover your garden cress in the event of a surprise late frost.

USDA Zone Info for Portland

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Portland

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