One of the best tools that you have as gardeners to help us figure out 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 looking at the USDA zone info for Tualatin.

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 really shouldn't plant tropical hibiscus until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant tropical hibiscus in Tualatin 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. You probably don't want to wait any later than that or else your tropical hibiscus may not have a chance to grow to maturity. If you are starting your tropical hibiscus indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Since the USDA zone info for Tualatin is just an average the actual date of last frost changes from year to year. Half of the time in Tualatin last frost occurs after March 15 so make sure that you are prepared to cover your tropical hibiscus if you have a surprise late frost.

USDA Zone Info for Tualatin

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 Tualatin

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