The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's possible to determine when it's the best time to plant browallia by using the USDA zone info for Portland.

Planting Calendar for Browallia

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

Since browallia require warm weather you must wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant browallia 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 browallia and expect a good harvest is probably August. If you wait any later than that and your browallia may not have a chance to really do well. Starting your browallia indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on March 15 in Portland. In the coldest months of winter you should expect an average low temperature of 15°F.

Since the USDA zone info for Portland is just an average the actual date of last frost is different every year. Half of the time in Portland you get surprised by a frost after March 15 so always be ready to cover your browallia in the event of a late frost.

USDA Zone Info for Portland

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 Portland

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