One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Duluth you can figure out when you can plant mustard by checking out the USDA zone info.

Planting Calendar for Mustard

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

Mustard are not cold tolerant which means that you must wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant mustard in Duluth is May. However, you really should wait until June 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. If you wait any later than that and your mustard may not have a chance to really do well. If you are starting your mustard indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Duluth the average date of last frost happens on May 15. In the coldest months of winter you can expect an average low temperature of -30°F.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Duluth and it can change quite a bit from year to year. Half of the time in Duluth you get surprised by a frost after May 15 so be sure to be ready to cover your mustard in the event of a surprise late frost.

USDA Zone Info for Duluth

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 Duluth

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