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 osteospermum in Portland can be figured out by using the USDA zone info.

Planting Calendar for Osteospermum

Frost tolerance for osteospermum:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

You can plant osteospermum just a bit earlier in the year because they do well in moderate cold.

The earliest that you can plant osteospermum in Portland is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant osteospermum and expect a good harvest is probably October. Any later than that and your osteospermum may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your osteospermum indoors.

Last Frost Date

The average date of last frost is February 15 in Portland. You should expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Portland is an average the actual date of last frost is different every year. Since half of the time in Portland it frosts late in the year after February 15 be ready to cover your osteospermum 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.