The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By checking out the USDA zone info for Vacaville it's possible to estimate when it's possible to 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.

You can plant bunching onions just a tiny bit earlier in the year because they do ok in moderate cold.

The earliest that you can plant bunching onions in Vacaville 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

In Vacaville the average date of last frost happens on February 15. In the coldest months of winter you can expect an average low temperature of 25°F.

Just be sure to remember that USDA zone info for Vacaville is not always accurate and the actual date of last frost is different every year. Since half of the time in Vacaville there is a last frost after February 15 be ready to protect your bunching onions if you have one of those late frosts.

USDA Zone Info for Vacaville

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Vacaville

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