One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of getting a good idea when you can plant mustard greens is to use the USDA zone info for Aspen.

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 just a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant mustard greens in Aspen 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. Any later than that and your mustard greens may not have a chance to grow to maturity. Starting your mustard greens indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost is on April 15 in Aspen. You can expect an average low temperature of -15°F in the coldest months of winter.

Always keep in mind that USDA zone info for Aspen is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Aspen you get surprised by a frost after April 15 so make sure that you are ready to cover your mustard greens if you have a surprise late frost.

USDA Zone Info for Aspen

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 Aspen

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