Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By reviewing the USDA zone info for Knoxville you will be able to estimate when to plant tropical hibiscus.

Planting Calendar for Tropical Hibiscus

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

Tropical Hibiscus are not cold tolerant which means that it is important to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant tropical hibiscus in Knoxville 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 really do well. Starting your tropical hibiscus indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Knoxville. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Knoxville is not always accurate the actual date of last frost is different every year. Since half of the time in Knoxville you get a frost after April 15 be ready to protect your tropical hibiscus in the event of one of those late frosts.

USDA Zone Info for Knoxville

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 Knoxville

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