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 Luis can be reffered to in order to figure out when you can 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.

Since pearl onions are barely cold tolerant you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant pearl onions in San Luis 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. You probably don't want to wait any later than that or else your pearl onions may not have a chance to fully mature. You can get started a little bit earlier by starting your pearl onions indoors.

Last Frost Date

The average date of last frost is January 31 in San Luis. You should expect an average low temperature of 30°F in the coldest months of winter.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for San Luis and it can change quite a bit from year to year. Since half of the time in San Luis you get surprised by a frost after January 31 be ready to protect your pearl onions in the event of a surprise late frost.

USDA Zone Info for San Luis

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 Luis

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