One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

You should be able to determine when it's a good idea to plant mustard by looking at the USDA zone info for Gaithersburg.

Planting Calendar for Mustard

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

It's not a good idea to plant mustard until after the last frost because they require warm weather.

The earliest that you can plant mustard in Gaithersburg 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. If you wait any later than that and your mustard may not have a chance to fully mature. You can get started a few weeks earlier by starting your mustard indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Gaithersburg. In the coldest months of winter you should expect an average low temperature of 0°F.

Remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Gaithersburg and it will vary from year to year. Half of the time in Gaithersburg you get a frost after April 15 so be sure to be ready to cover your mustard in the event of one of those late frosts.

USDA Zone Info for Gaithersburg

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Gaithersburg

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