One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first opportunity to plant salpiglossis in Portland should be estimated by referring to the USDA zone info.

Planting Calendar for Salpiglossis

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

It's a bad idea to plant salpiglossis until after the last frost when the weather gets warmer because they are not cold tolerant.

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. If you are starting your salpiglossis indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Portland. It might get as low as -15°F during the coldest months of winter.

It's important to remember that USDA zone info for Portland is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Portland you get surprised by a frost after April 15 so make sure that you are ready to protect your salpiglossis if you have a surprise late frost.

USDA Zone Info for Portland

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°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 -10°F.

Plants to Grow in Portland

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