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.

The USDA zone info for Washington can be read to determine when to plant tropical hibiscus.

Planting Calendar for Tropical Hibiscus

Frost tolerance for tropical hibiscus:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

You really shouldn't plant tropical hibiscus until after all chance of frost has passed because they require warm weather.

The earliest that you can plant tropical hibiscus in Washington 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 little bit earlier by starting your tropical hibiscus indoors.

Last Frost Date

The average date of last frost is April 15 in Washington. In the coldest months of winter you should expect an average low temperature of -15°F.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Washington and it will vary from year to year. Half of the time in Washington there is a last frost after April 15 so be sure to be ready to cover your tropical hibiscus if you have a late frost.

USDA Zone Info for Washington

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°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 -10°F.

Plants to Grow in Washington

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