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.

The earliest that you can plant stevia in Portland should be estimated by checking out the USDA zone info.

Planting Calendar for Stevia

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

Stevia require warm weather which tells us that it's necessary to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant stevia 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 stevia and expect a good harvest is probably September. Any later than that and your stevia may not have a chance to grow to maturity. If you are starting your stevia indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Portland the average date of last frost happens on February 15. You should expect an average low temperature of 25°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 changes from year to year. Half of the time in Portland you get a frost after February 15 so be sure to be ready to cover your stevia if you have a surprise late frost.

USDA Zone Info for Portland

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Portland

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