Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's possible to determine when you can plant mustard greens by using the USDA zone info for Havre.

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

The earliest that you can plant mustard greens in Havre 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 mustard greens and expect a good harvest is probably August. 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

The average date of last frost is May 15 in Havre. In the coldest months of winter you should expect an average low temperature of -30°F.

Just be sure to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Havre and it is different every year. Half of the time in Havre there is a last frost after May 15 so just be sure to be ready to cover your mustard greens in the event of a surprise late frost.

USDA Zone Info for Havre

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Havre

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