One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to determine when you can plant tree onions by referring to the USDA zone info for Lake Forest.

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 more sensitive plants.

The earliest that you can plant tree onions in Lake Forest 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 grow to maturity. You can get started a couple of weeks earlier by starting your tree onions indoors.

Last Frost Date

The average date of last frost is January 31 in Lake Forest. In the coldest months of winter you should expect an average low temperature of 30°F.

It's important to remember that USDA zone info for Lake Forest is not always accurate and the actual date of last frost will vary from year to year. Half of the time in Lake Forest you get a frost after January 31 so make sure that you are ready to protect your tree onions if you have one of those late frosts.

USDA Zone Info for Lake Forest

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 Lake Forest

You may be interested in your other planting guides for Lake Forest.