Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Nogales can be reviewed to figure out when to plant onions.

Planting Calendar for Onions

Frost tolerance for onions:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Onions do well in cold which tells us that you can plant them a quite a bit earlier than other frost tender plants.

The earliest that you can plant onions in Nogales 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 onions and expect a good harvest is probably September. Any later than that and your onions may not have a chance to really do well. You can get started a couple of weeks earlier by starting your onions indoors.

Last Frost Date

On average the last frost has passed is on March 15 in Nogales. You should expect an average low temperature of 10°F in the coldest months of winter.

Since the USDA zone info for Nogales may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in Nogales last frost occurs after March 15 be ready to protect your onions if you have a late frost.

USDA Zone Info for Nogales

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Nogales

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