One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

One way of estimating when to plant streptocarpella is to consult the USDA zone info for Portland.

Planting Calendar for Streptocarpella

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

You should not plant streptocarpella until after the last frost because they are not cold tolerant.

The earliest that you can plant streptocarpella 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 streptocarpella and expect a good harvest is probably September. You probably don't want to wait any later than that or else your streptocarpella may not have a chance to really do well. You can get started a few weeks earlier by starting your streptocarpella indoors.

Last Frost Date

The average date of last frost is February 15 in Portland. In the coldest months of winter you should expect an average low temperature of 25°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 last frost occurs after February 15 so make sure that you are ready to protect your streptocarpella 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.