Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. 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 should be reffered to in order to estimate when you can plant bunching onions.

Planting Calendar for Bunching Onions

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

Bunching Onions do ok in moderate cold which means that you can plant them slightly earlier than plants that are more sensitive to the cold.

The earliest that you can plant bunching 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 bunching onions and expect a good harvest is probably September. You probably don't want to wait any later than that or else your bunching onions may not have a chance to fully mature. Starting your bunching onions indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost is on January 31 in San Luis. In the coldest months of winter you should expect an average low temperature of 30°F.

Since the USDA zone info for San Luis is not always accurate the actual date of last frost is different every year. Since half of the time in San Luis you get a frost after January 31 be ready to cover your bunching 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.