One of the best tools that you have as gardeners to help us determine 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.

You should be able to figure out when to plant tropical hibiscus by referring to the USDA zone info for Corvallis.

Planting Calendar for Tropical Hibiscus

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

You can not plant tropical hibiscus until after the last frost because they do not do well in cold weather.

The earliest that you can plant tropical hibiscus in Corvallis is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant tropical hibiscus and expect a good harvest is probably August. If you wait any later than that and your tropical hibiscus may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your tropical hibiscus indoors.

Last Frost Date

The average date of last frost is March 15 in Corvallis. In the coldest months of winter you can expect an average low temperature of 15°F.

Just be sure to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Corvallis and it can change quite a bit from year to year. Since half of the time in Corvallis there is a last frost after March 15 be ready to cover your tropical hibiscus in the event of a late frost.

USDA Zone Info for Corvallis

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 Corvallis

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