The USDA Zone info is a great tool for gardeners to help us estimate 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 reviewed to figure out when it's the best time to plant calibrachoa.

Planting Calendar for Calibrachoa

Frost tolerance for calibrachoa:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since calibrachoa do ok in moderate cold you can plant them slightly earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant calibrachoa in Knoxville is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant calibrachoa and expect a good harvest is probably August. Any later than that and your calibrachoa may not have a chance to grow to maturity. If you are starting your calibrachoa indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Knoxville the average date of last frost happens on April 15. It might get as low as 0°F during the coldest months of winter.

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 Knoxville and it changes from year to year. Since half of the time in Knoxville you get surprised by a frost after April 15 be ready to cover your calibrachoa in the event of one of those late frosts.

USDA Zone Info for Knoxville

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Knoxville

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