One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The best time to plant salpiglossis in Portland can be figured out by using the USDA zone info.

Planting Calendar for Salpiglossis

Frost tolerance for salpiglossis:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since salpiglossis 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 salpiglossis 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 salpiglossis and expect a good harvest is probably August. You probably don't want to wait any later than that or else your salpiglossis may not have a chance to really do well. You can get started a little bit earlier by starting your salpiglossis indoors.

Last Frost Date

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

Keep in mind that USDA zone info for Portland is an average and the actual date of last frost is different every year. Since half of the time in Portland there is a last frost after March 15 be ready to cover your salpiglossis in the event of a surprise 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.