One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of estimating when it's a good idea to plant bunching onions is to look at the USDA zone info for San Marcos.

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 some cold which tells us that you can plant them slightly earlier in the year than other plants that might not handle the cold.

The earliest that you can plant bunching onions in San Marcos is March. However, you really should wait until April 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 August. You probably don't want to wait any later than that or else your bunching onions may not have a chance to really do well. You can get started a couple of weeks earlier by starting your bunching onions indoors.

Last Frost Date

In San Marcos the average date of last frost happens on March 15. You should expect an average low temperature of 15°F in the coldest months of winter.

Keep in mind that USDA zone info for San Marcos is an average and the actual date of last frost will vary from year to year. Half of the time in San Marcos it frosts late in the year after March 15 so be sure to be ready to protect your bunching onions in the event of one of those late frosts.

USDA Zone Info for San Marcos

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in San Marcos

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