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

A common way of determining when it's the best time to plant bunching onions is to consult the USDA zone info for Covina.

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 tend to make it in very little cold which means that you can plant them just a tiny bit earlier in the year than more sensitive plants.

The earliest that you can plant bunching onions in Covina 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 really do well. Starting your bunching onions indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Covina the average date of last frost happens on January 31. It might get as low as 30°F during the coldest months of winter.

Since the USDA zone info for Covina is just an average the actual date of last frost is different every year. Half of the time in Covina you get surprised by a frost after January 31 so always be ready to cover your bunching onions if you have a late frost.

USDA Zone Info for Covina

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Covina

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