The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Portland can be used to estimate when you can plant hardy hibiscus.

Planting Calendar for Hardy Hibiscus

Frost tolerance for hardy hibiscus:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Hardy Hibiscus are one of those plants that can tolerate quite a bit of cold weather which tells us that you can get them planted much earlier than other plants that might not handle the cold.

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

The last month that you can plant hardy hibiscus and expect a good harvest is probably September. Any later than that and your hardy hibiscus may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your hardy hibiscus indoors.

Last Frost Date

In Portland the average date of last frost happens on March 15. It might get as low as 15°F during the coldest months of winter.

Remember that USDA zone info for Portland is not always accurate and the actual date of last frost is different every year. Half of the time in Portland there is a last frost after March 15 so be sure to be ready to cover your hardy hibiscus if you have a surprise late frost.

USDA Zone Info for Portland

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Portland

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