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.

By referring to the USDA zone info for Cambridge it's possible to figure out when you can plant dahlias.

Planting Calendar for Dahlias

Frost tolerance for dahlias:	Not tolerant of frost.
When to plant:	After the last frost has passed.

It's probably a bad idea to plant dahlias until after the last frost when the weather gets warmer because they do not do well in cold weather.

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

The last month that you can plant dahlias and expect a good harvest is probably August. Any later than that and your dahlias may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your dahlias indoors.

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 is an average the actual date of last frost changes from year to year. Since half of the time in Cambridge you get surprised by a frost after May 15 be ready to cover your dahlias in the event of 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.