One of the first steps you take when you are making a decision about 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.

In Cambridge you can determine when it's possible to plant lemon balm by checking out the USDA zone info.

Planting Calendar for Lemon balm

Frost tolerance for lemon balm:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since lemon balm are barely cold tolerant you can plant them a bit earlier in the year than other plants that might not handle the cold.

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

Last Frost Date

The average date of last frost is May 15 in Cambridge. In the coldest months of winter you should expect an average low temperature of -30°F.

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 May 15 so just be sure to be ready to protect your lemon balm if you have one of those late frosts.

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.