One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first opportunity to plant tree onions in Aliso Viejo can be figured out 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 slightly earlier in the year than other frost tender plants.

The earliest that you can plant tree onions in Aliso Viejo 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 really do well. Starting your tree onions indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is January 31 in Aliso Viejo. You should expect an average low temperature of 30°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 Aliso Viejo and it can change quite a bit from year to year. Half of the time in Aliso Viejo you get a frost after January 31 so just be sure to be ready to cover your tree onions in the event of one of those late frosts.

USDA Zone Info for Aliso Viejo

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Aliso Viejo

You may be interested in your other planting guides for Aliso Viejo.