Before planting it is a good idea to find your USDA Zone info to determine 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.

The USDA zone info for Watertown should be used to estimate when to plant balloon flower.

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.

You can plant balloon flower just a tiny bit earlier in the year because they are barely cold tolerant.

The earliest that you can plant balloon flower in Watertown 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. Any later than that and your balloon flower may not have a chance to really do well. Starting your balloon flower indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on May 15 in Watertown. In the coldest months of winter you should expect an average low temperature of -25°F.

Remember that USDA zone info for Watertown is an average and the actual date of last frost changes from year to year. Half of the time in Watertown you get surprised by a frost after May 15 so just be sure to be ready to protect your balloon flower in the event of one of those late frosts.

USDA Zone Info for Watertown

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Watertown

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