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.

A way of estimating when it's the best time to plant tree onions is to examine the USDA zone info for Butner.

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.

Since tree onions do ok in moderate cold you can plant them slightly earlier in the year than other frost tender plants.

The earliest that you can plant tree onions in Butner 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. You probably don't want to wait any later than that or else your tree onions may not have a chance to grow to maturity. If you are starting your tree onions indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Butner. In the coldest months of winter you should expect an average low temperature of 5°F.

Just be sure to remember that USDA zone info for Butner may not be accurate from year to year and the actual date of last frost is different every year. Since half of the time in Butner you get surprised by a frost after April 15 be ready to cover your tree onions if you have one of those late frosts.

USDA Zone Info for Butner

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 Butner

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