One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant tree onions in Cottonwood can be determined by checking out the USDA zone info.

Planting Calendar for Tree onions

Frost tolerance for tree onions:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Tree onions do ok in moderate cold which means that you can get them planted just a bit earlier than other frost tender plants.

The earliest that you can plant tree onions in Cottonwood is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant tree onions and expect a good harvest is probably August. Any later than that and your tree onions may not have a chance to fully mature. Starting your tree onions indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is March 15 in Cottonwood. You should expect an average low temperature of 15°F in the coldest months of winter.

Since the USDA zone info for Cottonwood is an average the actual date of last frost will vary from year to year. Since half of the time in Cottonwood last frost occurs after March 15 be ready to cover your tree onions in the event of a late frost.

USDA Zone Info for Cottonwood

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in Cottonwood

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