Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. 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 determine when to plant dahlia by referring to the USDA zone info.

Planting Calendar for Dahlia

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

Since dahlia require warm weather it's necessary to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant dahlia 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 dahlia and expect a good harvest is probably August. You probably don't want to wait any later than that or else your dahlia may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your dahlia indoors.

Last Frost Date

In Cambridge the average date of last frost happens on April 15. You can expect an average low temperature of 5°F in the coldest months of winter.

Since the USDA zone info for Cambridge is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Cambridge you get a frost after April 15 be ready to cover your dahlia if you have a late frost.

USDA Zone Info for Cambridge

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Cambridge

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