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

A common way of figuring out when to plant purple rock cress is to check out the USDA zone info for Herkimer.

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 very cold tolerant you can plant them earlier in the year than other frost tender plants.

The earliest that you can plant purple rock cress in Herkimer 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 grow to maturity. If you are starting your purple rock cress indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Herkimer. It might get as low as -15°F during the coldest months of winter.

It's important to remember that USDA zone info for Herkimer is an average and the actual date of last frost is different every year. Since half of the time in Herkimer last frost occurs after April 15 be ready to protect your purple rock cress if you have a surprise late frost.

USDA Zone Info for Herkimer

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 Herkimer

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