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.

You should be able to determine when it's possible to plant bunching onions by using the USDA zone info for Presidio.

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 are barely cold tolerant 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 bunching onions in Presidio 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. You can get started a couple of weeks earlier by starting your bunching onions indoors.

Last Frost Date

The average date of last frost is February 15 in Presidio. You can expect an average low temperature of 20°F in the coldest months of winter.

Since the USDA zone info for Presidio is just an average the actual date of last frost is different every year. Since half of the time in Presidio it frosts late in the year after February 15 be ready to cover your bunching onions in the event of one of those late frosts.

USDA Zone Info for Presidio

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Presidio

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