One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Portland you can determine when to plant stoneseed by using the USDA zone info.

Planting Calendar for Stoneseed

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

Stoneseed are not cold tolerant which means that you really should wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant stoneseed 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 stoneseed and expect a good harvest is probably August. If you wait any later than that and your stoneseed may not have a chance to fully mature. If you are starting your stoneseed indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is April 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 is an average the actual date of last frost is different every year. Since half of the time in Portland last frost occurs after April 15 be ready to protect your stoneseed in the event of 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.