One of the first steps you take when you are estimating 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 earliest that you can plant mustard in Denver can be determined by referring to the USDA zone info.

Planting Calendar for Mustard

Frost tolerance for mustard:	Not tolerant of frost.
When to plant:	After the last frost has passed.

It's a bad idea to plant mustard until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant mustard in Denver is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant mustard and expect a good harvest is probably August. Any later than that and your mustard may not have a chance to grow to maturity. Starting your mustard indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Denver 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.

Just be sure to remember that USDA zone info for Denver is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Denver last frost occurs after April 15 so just be sure to be ready to protect your mustard if you have one of those late frosts.

USDA Zone Info for Denver

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 Denver

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