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.

By referring to the USDA zone info for Portland you will be able to determine when it's possible to plant bittercress.

Planting Calendar for Bittercress

Frost tolerance for bittercress:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Bittercress do well in mild cold which means that you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant bittercress 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 bittercress and expect a good harvest is probably August. Any later than that and your bittercress may not have a chance to really do well. Starting your bittercress 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. You can expect an average low temperature of -15°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Portland and it is different every year. Since half of the time in Portland last frost occurs after April 15 be ready to protect your bittercress if you have a late frost.

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.