Before planting it is a good idea to find your USDA Zone info to figure out 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.

In Chattanooga you can figure out when it's the best time to plant tree onions by checking out the USDA zone info.

Planting Calendar for Tree onions

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

Tree onions do ok in very little cold which tells us that you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant tree onions in Chattanooga 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 tree onions and expect a good harvest is probably August. If you wait any later than that and your tree onions may not have a chance to fully mature. If you are starting your tree onions indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Chattanooga the average date of last frost happens on April 15. You should expect an average low temperature of 5°F in the coldest months of winter.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Chattanooga and it changes from year to year. Half of the time in Chattanooga it frosts late in the year after April 15 so always be ready to cover your tree onions if you have one of those late frosts.

USDA Zone Info for Chattanooga

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Chattanooga

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