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

The USDA zone info for Scottsdale should be reviewed 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 do ok in moderate cold you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant bunching onions in Scottsdale 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. Starting your bunching onions indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Scottsdale the average date of last frost happens on February 15. You should expect an average low temperature of 25°F in the coldest months of winter.

Remember that USDA zone info for Scottsdale is an average and the actual date of last frost changes from year to year. Since half of the time in Scottsdale it frosts late in the year after February 15 be ready to cover your bunching onions if you have a surprise late frost.

USDA Zone Info for Scottsdale

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 Scottsdale

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