One of the first steps you take when you are estimating 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.

In Portland you can determine when it's the best time to plant portulaca by using the USDA zone info.

Planting Calendar for Portulaca

Frost tolerance for portulaca:	Not tolerant of frost.
When to plant:	After the last frost.

It's a bad idea to plant portulaca until after all chance of frost has passed because they do not do well in cold weather.

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

The last month that you can plant portulaca and expect a good harvest is probably August. You probably don't want to wait any later than that or else your portulaca may not have a chance to fully mature. You can get started a few weeks earlier by starting your portulaca indoors.

Last Frost Date

In Portland the average date of last frost happens on April 15. You should expect an average low temperature of 0°F in the coldest months of winter.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Portland and it changes from year to year. Half of the time in Portland you get a frost after April 15 so make sure that you are prepared to protect your portulaca in the event of one of those late frosts.

USDA Zone Info for Portland

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Portland

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