The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Watertown you can determine when you can plant borage by using the USDA zone info.

Planting Calendar for Borage

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

You can plant borage just a bit earlier in the year because they are moderately cold tolerant.

The earliest that you can plant borage in Watertown 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 borage and expect a good harvest is probably August. Any later than that and your borage may not have a chance to grow to maturity. Starting your borage indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Watertown the average date of last frost happens on May 15. In the coldest months of winter you can expect an average low temperature of -30°F.

Since the USDA zone info for Watertown is just an average the actual date of last frost will vary from year to year. Half of the time in Watertown you get surprised by a frost after May 15 so always be ready to cover your borage if you have a late frost.

USDA Zone Info for Watertown

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 Watertown

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