One of the best tools that you have as gardeners to help us determine 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.

The USDA zone info for San Dimas can be read to estimate when to plant pearl onions.

Planting Calendar for Pearl onions

Frost tolerance for pearl onions:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

You can plant pearl onions just a tiny 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 pearl onions in San Dimas 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 pearl onions and expect a good harvest is probably September. Any later than that and your pearl onions may not have a chance to grow to maturity. Starting your pearl onions indoors is a great way to get them started a few weeks earlier.

Last Frost Date

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

Since the USDA zone info for San Dimas is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in San Dimas there is a last frost after January 31 so always be ready to cover your pearl onions in the event of a late frost.

USDA Zone Info for San Dimas

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 San Dimas

You may be interested in your other planting guides for San Dimas.