One of the first steps you take when you are estimating 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.

The first chance to plant purple coneflower in Cambridge should be figured out by looking at the USDA zone info.

Planting Calendar for Purple Coneflower

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

Purple Coneflower do well in mild cold which means that you can plant them just a tiny bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant purple coneflower 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 purple coneflower and expect a good harvest is probably August. If you wait any later than that and your purple coneflower may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your purple coneflower indoors.

Last Frost Date

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

Since the USDA zone info for Cambridge may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in Cambridge there is a last frost after May 15 be ready to cover your purple coneflower 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.