Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. 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 estimate when to plant mustard greens by looking at the USDA zone info for Mercer Island.

Planting Calendar for Mustard greens

Frost tolerance for mustard greens:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Mustard greens do well in moderate cold which means that you can start planting them earlier than more sensitive plants.

The earliest that you can plant mustard greens in Mercer Island 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. If you wait any later than that and your mustard greens may not have a chance to really do well. If you are starting your mustard greens indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on March 15 in Mercer Island. It might get as low as 15°F during the coldest months of winter.

Since the USDA zone info for Mercer Island is just an average the actual date of last frost changes from year to year. Half of the time in Mercer Island it frosts late in the year after March 15 so make sure that you are prepared to protect your mustard greens if you have a surprise late frost.

USDA Zone Info for Mercer Island

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Mercer Island

You may be interested in your other planting guides for Mercer Island.