One of the first steps you take when you are figuring out your gardening schedule is find your 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 way of figuring out when to plant rosemary is to refer to the USDA zone info for Cambridge.

Planting Calendar for Rosemary

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

Rosemary tend to make it in cold weather which means that you can plant them earlier in the year than plants that are more sensitive to the cold.

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

The last month that you can plant rosemary and expect a good harvest is probably August. Any later than that and your rosemary may not have a chance to really do well. Starting your rosemary indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on May 15 in Cambridge. It might get as low as -30°F during the coldest months of winter.

Keep in mind that USDA zone info for Cambridge is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Cambridge you get surprised by a frost after May 15 so be sure to be ready to protect your rosemary if you have a surprise late frost.

USDA Zone Info for Cambridge

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Cambridge

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