One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. 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 salpiglossis in Portland should be determined by reviewing the USDA zone info.

Planting Calendar for Salpiglossis

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

Since salpiglossis require warm weather you must wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant salpiglossis 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 salpiglossis and expect a good harvest is probably September. Any later than that and your salpiglossis may not have a chance to fully mature. If you are starting your salpiglossis indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on February 15 in Portland. You can expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Portland is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Portland it frosts late in the year after February 15 so always be ready to protect your salpiglossis if you have one of those late frosts.

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.