The USDA Zone info is a great tool for gardeners to help us estimate 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.

By checking out the USDA zone info for Imperial Beach you should be able to determine when to plant tree onions.

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.

You can plant tree onions a bit earlier in the year because they are one of those plants that can tolerate a tiny bit of cold weather.

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

Last Frost Date

In Imperial Beach the average date of last frost happens on January 31. In the coldest months of winter you should expect an average low temperature of 35°F.

Since the USDA zone info for Imperial Beach is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Imperial Beach there is a last frost after January 31 be ready to cover your tree onions if you have one of those late frosts.

USDA Zone Info for Imperial Beach

Here is the info for USDA Zone 10b.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	35°F
Highest Expected Low	40°F

This means that on a really cold year, the coldest it will get is 35°F. On most years you should be prepared to experience lows near 40°F.

Plants to Grow in Imperial Beach

You may be interested in your other planting guides for Imperial Beach.