The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. 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 Knoxville should be read to determine when you can plant calla lily.

Planting Calendar for Calla Lily

Frost tolerance for calla lily:	Not tolerant of frost.
When to plant:	After the last frost has passed.

You should not plant calla lily until after the last frost has passed because they do not do well in cold weather.

The earliest that you can plant calla lily 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 calla lily and expect a good harvest is probably August. You probably don't want to wait any later than that or else your calla lily may not have a chance to really do well. If you are starting your calla lily indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Knoxville. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for Knoxville is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Knoxville it frosts late in the year after April 15 so always be ready to protect your calla lily if you have 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.