One of the best tools that you have as gardeners to help us figure out your gardening schedule is the 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.

You will be able to figure out when it's possible to plant rhubarb by reviewing the USDA zone info for Cambridge.

Planting Calendar for Rhubarb

Frost tolerance for rhubarb:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since rhubarb are moderately 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 rhubarb in Cambridge is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant rhubarb and expect a good harvest is probably August. You probably don't want to wait any later than that or else your rhubarb may not have a chance to really do well. Starting your rhubarb indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Cambridge the average date of last frost happens on May 15. It might get as low as -30°F during the coldest months of winter.

Always keep in mind that USDA zone info for Cambridge is not always accurate and the actual date of last frost changes from year to year. Half of the time in Cambridge there is a last frost after May 15 so be sure to be ready to cover your rhubarb if you have a 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.