The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's a good idea to determine when it's a good idea to plant tree onions by looking at the USDA zone info for Oakland.

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 one of those plants that can tolerate a tiny bit of cold weather which means that you can start planting them slightly earlier than plants that are more sensitive to the cold.

The earliest that you can plant tree onions in Oakland 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 grow to maturity. If you are starting your tree onions indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is January 31 in Oakland. You can expect an average low temperature of 30°F in 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 Oakland and it will vary from year to year. Half of the time in Oakland you get surprised by a frost after January 31 so always be ready to cover your tree onions if you have one of those late frosts.

USDA Zone Info for Oakland

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 Oakland

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