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.

In Portland you can estimate when it's the best time to plant hibiscus by reviewing the USDA zone info.

Planting Calendar for Hibiscus

Frost tolerance for hibiscus:	Not tolerant of frost.
When to plant:	After the last frost.

Hibiscus require warm weather which tells us that you really should wait until it warms up after the last frost before you can plant them.

The earliest that you can plant hibiscus 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 hibiscus and expect a good harvest is probably September. If you wait any later than that and your hibiscus may not have a chance to fully mature. Starting your hibiscus indoors is a great way to get them started a few weeks earlier.

Last Frost Date

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

Always keep in mind that USDA zone info for Portland is an average and the actual date of last frost will vary from year to year. Since half of the time in Portland last frost occurs after February 15 be ready to cover your hibiscus 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.