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

You can estimate when it's a good idea to plant purple rock cress in Crystal Lake by referring to the USDA zone info.

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 quite a bit earlier in the year than other frost tender plants.

The earliest that you can plant purple rock cress in Crystal Lake 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 really do well. You can get started a couple of weeks earlier by starting your purple rock cress indoors.

Last Frost Date

The average date of last frost is April 15 in Crystal Lake. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Crystal Lake may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Crystal Lake it frosts late in the year after April 15 so make sure that you are ready to protect your purple rock cress in the event of a surprise late frost.

USDA Zone Info for Crystal Lake

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 Crystal Lake

You may be interested in your other planting guides for Crystal Lake.