The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. 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 estimate when to plant torenia by using the USDA zone info.

Planting Calendar for Torenia

Frost tolerance for torenia:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Since torenia are not cold tolerant you must wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant torenia 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 torenia and expect a good harvest is probably September. If you wait any later than that and your torenia may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your torenia indoors.

Last Frost Date

On average all chance of frost has passed is on February 15 in Portland. It might get as low as 25°F during the coldest months of winter.

Keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Portland and it is different every year. Half of the time in Portland there is a last frost after February 15 so always be ready to protect your torenia 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.