Before planting it is a good idea to find your USDA Zone info to estimate 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.

A common way of determining when you can plant erysimum is to refer to the USDA zone info for Plymouth.

Planting Calendar for Erysimum

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

Erysimum do well in moderate cold which means that you can get them planted earlier than plants that are more sensitive to the cold.

The earliest that you can plant erysimum in Plymouth 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 erysimum and expect a good harvest is probably September. You probably don't want to wait any later than that or else your erysimum may not have a chance to fully mature. If you are starting your erysimum indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Plymouth. In the coldest months of winter you can expect an average low temperature of -10°F.

Since the USDA zone info for Plymouth may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in Plymouth there is a last frost after April 15 be ready to cover your erysimum in the event of one of those late frosts.

USDA Zone Info for Plymouth

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Plymouth

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