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

A way of making a decision about when it's the best time to plant balloon flower is to check out the USDA zone info for Cambridge.

Planting Calendar for Balloon Flower

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

Balloon Flower do ok in moderate cold which means that you can start planting them slightly earlier than more sensitive plants.

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

Last Frost Date

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

It's important to remember that USDA zone info for Cambridge is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Cambridge it frosts late in the year after May 15 be ready to cover your balloon flower in the event of 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.