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 checking out the USDA zone info for Ionia it's possible to figure out when it's a good idea 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.

Purple Rock Cress do well in cold weather which tells us that you can plant them quite a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant purple rock cress in Ionia 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. Any later than that and your purple rock cress may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your purple rock cress indoors.

Last Frost Date

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

It's important to remember that USDA zone info for Ionia is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Ionia you get surprised by a frost after April 15 be ready to protect your purple rock cress in the event of one of those late frosts.

USDA Zone Info for Ionia

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 Ionia

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