The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of estimating when it's a good idea to plant tree onions is to consult the USDA zone info for Tolleson.

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 some cold which tells us that 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 Tolleson 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. 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 couple of weeks earlier.

Last Frost Date

In Tolleson the average date of last frost happens on February 15. In the coldest months of winter you can expect an average low temperature of 25°F.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Tolleson and it is different every year. Half of the time in Tolleson you get a frost after February 15 so always be ready to cover your tree onions if you have a surprise late frost.

USDA Zone Info for Tolleson

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Tolleson

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