One of the first steps you take when you are figuring out 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.

The USDA zone info for Castle Rock can be used to determine when it's the best time to plant mustard greens.

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 one of those plants that can tolerate a little bit of cold weather you can plant them just a bit earlier in the year than more sensitive plants.

The earliest that you can plant mustard greens in Castle Rock 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 really do well. You can get started a little bit earlier by starting your mustard greens indoors.

Last Frost Date

In Castle Rock 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.

Since the USDA zone info for Castle Rock is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Castle Rock last frost occurs after April 15 be ready to cover your mustard greens in the event of a late frost.

USDA Zone Info for Castle Rock

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 Castle Rock

You may be interested in your other planting guides for Castle Rock.