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.

In Waltham you can figure out when it's a good idea to plant crassula by looking at the USDA zone info.

Planting Calendar for Crassula

Frost tolerance for crassula:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

It's probably not a good idea to plant crassula until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant crassula in Waltham is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant crassula and expect a good harvest is probably August. You probably don't want to wait any later than that or else your crassula may not have a chance to fully mature. If you are starting your crassula indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Waltham. In the coldest months of winter you can expect an average low temperature of -10°F.

Always keep in mind that USDA zone info for Waltham is just an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Waltham you get a frost after April 15 so just be sure to be ready to cover your crassula if you have a late frost.

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.