Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Tustin you can determine when it's a good idea to plant bunching onions by using 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.

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 Tustin 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. 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

On average the last frost when the weather gets warmer is on January 31 in Tustin. It might get as low as 30°F during the coldest months of winter.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Tustin and it can change quite a bit from year to year. Since half of the time in Tustin you get surprised by a frost after January 31 be ready to protect your bunching onions if you have a surprise late frost.

USDA Zone Info for Tustin

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 Tustin

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