When to Plant Erysimum in Swarthmore, PA

One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By reviewing the USDA zone info for Swarthmore you should be able to figure out when you can plant erysimum.


Planting Calendar for Erysimum

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

Since erysimum do well in moderate cold you can plant them a little bit earlier in the year than other plants that might not handle the cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant erysimum
Possibly ok, but a risky time to plant erysimum
Probably not a good time to plant erysimum

The earliest that you can plant erysimum in Swarthmore 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 couple of weeks earlier.

Last Frost Date

In Swarthmore the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of 0°F.

Just be sure to remember that USDA zone info for Swarthmore is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Swarthmore you get a frost after April 15 so make sure that you are prepared to cover your erysimum if you have a late frost.

USDA Zone Info for Swarthmore

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 Low0°F
Highest Expected Low5°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 Swarthmore

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