One of the best tools that you have as gardeners to help us estimate 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.

In Orinda you can determine when it's possible to plant bunching onions by checking out the USDA zone info.

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 can survive in mild cold which tells us that you can plant them just a tiny bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant bunching onions in Orinda 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 fully mature. You can get started a few weeks earlier by starting your bunching onions indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in Orinda. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Orinda is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Orinda there is a last frost after February 15 so make sure that you are ready to protect your bunching onions if you have a late frost.

USDA Zone Info for Orinda

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 Orinda

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