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

You should be able to figure out when it's possible to plant euphorbia by looking at the USDA zone info for Portland.

Planting Calendar for Euphorbia

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

Since euphorbia are one of those plants that can tolerate a tiny bit of cold weather you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant euphorbia 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 euphorbia and expect a good harvest is probably August. You probably don't want to wait any later than that or else your euphorbia may not have a chance to fully mature. If you are starting your euphorbia indoors then you might be able to get away with starting them a couple of 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 0°F in the coldest months of winter.

Since the USDA zone info for Portland may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in Portland last frost occurs after April 15 be ready to protect your euphorbia if you have a late frost.

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.