One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's possible to determine when to plant tree onions by reviewing the USDA zone info for Westlake.

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 are barely cold tolerant which means that you can start planting them slightly earlier than other frost tender plants.

The earliest that you can plant tree onions in Westlake 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 fully mature. Starting your tree onions indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on February 15 in Westlake. It might get as low as 20°F during the coldest months of winter.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Westlake and it can change quite a bit from year to year. Since half of the time in Westlake there is a last frost after February 15 be ready to cover your tree onions if you have one of those late frosts.

USDA Zone Info for Westlake

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 Westlake

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