When to Plant Bunching Onions in American Canyon, CA

The USDA Zone info is a great tool for gardeners to help us determine 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.

The USDA zone info for American Canyon can be read 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.

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

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant bunching onions
Possibly ok, but a risky time to plant bunching onions
Probably not a good time to plant bunching onions

The earliest that you can plant bunching onions in American Canyon 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. If you wait any later than that and your bunching onions may not have a chance to grow to maturity. You can get started a little bit earlier by starting your bunching onions indoors.

Last Frost Date

In American Canyon the average date of last frost happens on February 15. It might get as low as 25°F during the coldest months of winter.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for American Canyon and it will vary from year to year. Half of the time in American Canyon there is a last frost after February 15 so make sure that you are prepared to protect your bunching onions if you have one of those late frosts.

USDA Zone Info for American Canyon

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 Low25°F
Highest Expected Low30°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 American Canyon

You may be interested in your other planting guides for American Canyon.