Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of getting a good idea when to plant trailing portulaca is to check out the USDA zone info for Lake Oswego.

Planting Calendar for Trailing Portulaca

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

You should not plant trailing portulaca until after all chance of frost has passed because they require warm weather.

The earliest that you can plant trailing portulaca in Lake Oswego 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 trailing portulaca and expect a good harvest is probably August. Any later than that and your trailing portulaca may not have a chance to grow to maturity. Starting your trailing portulaca indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Lake Oswego the average date of last frost happens on March 15. You should expect an average low temperature of 15°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 Lake Oswego and it will vary from year to year. Half of the time in Lake Oswego it frosts late in the year after March 15 so just be sure to be ready to protect your trailing portulaca in the event of a surprise late frost.

USDA Zone Info for Lake Oswego

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 Lake Oswego

You may be interested in your other planting guides for Lake Oswego.