One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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.

The earliest that you can plant mustard greens in Thornton should be figured out by referring to the USDA zone info.

Planting Calendar for Mustard greens

Frost tolerance for mustard greens:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since mustard greens are moderately cold tolerant you can plant them a little earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant mustard greens in Thornton 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 mustard greens and expect a good harvest is probably September. If you wait any later than that and your mustard greens may not have a chance to grow to maturity. If you are starting your mustard greens indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for Thornton may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in Thornton last frost occurs after April 15 be ready to protect your mustard greens 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.