One of the best tools that you have as gardeners to help us determine 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.

By reviewing the USDA zone info for Allegan you should be able to determine when it's possible to plant purple rock cress.

Planting Calendar for Purple Rock Cress

Frost tolerance for purple rock cress:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since purple rock cress are one of those plants that can tolerate quite a bit of cold weather you can plant them a lot earlier in the year than more sensitive plants.

The earliest that you can plant purple rock cress in Allegan 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 purple rock cress and expect a good harvest is probably September. You probably don't want to wait any later than that or else your purple rock cress may not have a chance to fully mature. Starting your purple rock cress indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Allegan and it can change quite a bit from year to year. Half of the time in Allegan you get a frost after April 15 so just be sure to be ready to cover your purple rock cress if you have one of those late frosts.

USDA Zone Info for Allegan

Here is the info for USDA Zone 5b.

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

Plants to Grow in Allegan

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