One of the first steps you take when you are determining 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.

A common way of estimating when it's a good idea to plant purple rock cress is to check out the USDA zone info for Trenton.

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.

You can plant purple rock cress a lot earlier in the year because they are very cold tolerant.

The earliest that you can plant purple rock cress in Trenton 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. Starting your purple rock cress indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Trenton. It might get as low as 0°F during the coldest months of winter.

Since the USDA zone info for Trenton is not always accurate the actual date of last frost changes from year to year. Half of the time in Trenton you get surprised by a frost after April 15 so be sure to be ready to cover your purple rock cress in the event of one of those late frosts.

USDA Zone Info for Trenton

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 Low	0°F
Highest Expected Low	5°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 Trenton

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