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

The earliest that you can plant erysimum in Zone 6a can be estimated by checking out the USDA zone info.

Planting Calendar for Erysimum

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

Erysimum do ok in mild cold which tells us that you can plant them a little bit earlier in the year than other frost tender plants.

The earliest that you can plant erysimum in Zone 6a 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. Any later than that and your erysimum may not have a chance to really do well. If you are starting your erysimum indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Zone 6a. In the coldest months of winter you can expect an average low temperature of -10°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 Zone 6a and it will vary from year to year. Since half of the time in Zone 6a it frosts late in the year after April 15 be ready to cover your erysimum in the event of one of those late frosts.

USDA Zone Info for Zone 6a

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 Zone 6a

You may be interested in your other planting guides for Zone 6a.