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 first opportunity to plant bunching onions in Tempe should be estimated by looking at 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 slightly earlier in the year because they are barely cold tolerant.

The earliest that you can plant bunching onions in Tempe 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 fully mature. If you are starting your bunching onions indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Tempe the average date of last frost happens on February 15. In the coldest months of winter you can expect an average low temperature of 25°F.

Since the USDA zone info for Tempe is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Tempe it frosts late in the year after February 15 be ready to protect your bunching onions in the event of a surprise late frost.

USDA Zone Info for Tempe

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 Tempe

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