The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. 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 making a decision about when to plant shallots is to consult the USDA zone info for Thornton.

Planting Calendar for Shallots

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

Shallots are barely cold tolerant which means that you can start planting them slightly earlier than other plants that might not handle the cold.

The earliest that you can plant shallots in Thornton 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 shallots and expect a good harvest is probably August. You probably don't want to wait any later than that or else your shallots may not have a chance to grow to maturity. Starting your shallots indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Thornton the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -15°F.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Thornton and it is different every year. Half of the time in Thornton you get a frost after April 15 so make sure that you are prepared to cover your shallots if you have a surprise late frost.

USDA Zone Info for Thornton

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°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 -10°F.

Plants to Grow in Thornton

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