Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The best time to plant tree onions in Slidell can be determined by reviewing 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.

Since tree onions are barely cold tolerant you can plant them just a tiny bit earlier in the year than other frost tender plants.

The earliest that you can plant tree onions in Slidell is February. However, you really should wait until March 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 September. If you wait any later than that and your tree onions may not have a chance to really do well. You can get started a little bit earlier by starting your tree onions indoors.

Last Frost Date

The average date of last frost is February 15 in Slidell. You should expect an average low temperature of 20°F in the coldest months of winter.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Slidell and it will vary from year to year. Half of the time in Slidell there is a last frost after February 15 so always be ready to cover your tree onions if you have a late frost.

USDA Zone Info for Slidell

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Slidell

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