Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. 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 the best time to plant rock cress in Waltham by using the USDA zone info.

Planting Calendar for Rock Cress

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

Rock Cress are one of those plants that can tolerate quite a bit of cold weather which tells us that you can start planting them much earlier than other plants that might not handle the cold.

The earliest that you can plant rock cress in Waltham 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 rock cress and expect a good harvest is probably September. Any later than that and your rock cress may not have a chance to grow to maturity. You can get started a little bit earlier by starting your rock cress indoors.

Last Frost Date

The average date of last frost is April 15 in Waltham. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Waltham is just an average the actual date of last frost is different every year. Since half of the time in Waltham you get a frost after April 15 be ready to cover your rock cress if you have one of those late frosts.

USDA Zone Info for Waltham

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Waltham

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