The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to determine when you can plant larkspur by looking at the USDA zone info for Cambridge.

Planting Calendar for Larkspur

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

Larkspur tend to make it in a bit of cold which means that you can plant them quite a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant larkspur 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 larkspur and expect a good harvest is probably September. You probably don't want to wait any later than that or else your larkspur may not have a chance to really do well. You can get started a few weeks earlier by starting your larkspur indoors.

Last Frost Date

The average date of last frost is April 15 in Cambridge. You can expect an average low temperature of -10°F in the coldest months of winter.

It's important to remember that USDA zone info for Cambridge is an average and the actual date of last frost is different every year. Half of the time in Cambridge you get surprised by a frost after April 15 so be sure to be ready to cover your larkspur if you have a late frost.

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.