One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of getting a good idea when you can plant bunching onions is to look at the USDA zone info for Alamosa.

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 more sensitive plants.

The earliest that you can plant bunching onions in Alamosa is April. However, you really should wait until May 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 August. You probably don't want to wait any later than that or else your bunching onions may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your bunching onions indoors.

Last Frost Date

The average date of last frost is May 15 in Alamosa. You should expect an average low temperature of -25°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Alamosa may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in Alamosa it frosts late in the year after May 15 so always be ready to cover your bunching onions in the event of one of those late frosts.

USDA Zone Info for Alamosa

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°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 -20°F.

Plants to Grow in Alamosa

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