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 Cambridge you can figure out when you can plant sweet williams by looking at the USDA zone info.

Planting Calendar for Sweet Williams

Frost tolerance for sweet williams:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Sweet Williams are one of those plants that can tolerate a little bit of cold weather which means that you can plant them earlier than other plants that might not handle the cold.

The earliest that you can plant sweet williams in Cambridge 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 sweet williams and expect a good harvest is probably September. Any later than that and your sweet williams may not have a chance to fully mature. If you are starting your sweet williams indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Since the USDA zone info for Cambridge may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Cambridge there is a last frost after April 15 so just be sure to be ready to protect your sweet williams in the event of one of those late frosts.

USDA Zone Info for Cambridge

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 Cambridge

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