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.

A common way of estimating when it's a good idea to plant borage is to look at the USDA zone info for Watertown.

Planting Calendar for Borage

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

Borage can survive in mild cold which tells us that you can plant them a little earlier in the year than other plants that might not handle the cold.

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. If you wait any later than that and your borage may not have a chance to fully mature. If you are starting your borage indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is May 15 in Watertown. In the coldest months of winter you can expect an average low temperature of -25°F.

Since the USDA zone info for Watertown is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Watertown it frosts late in the year after May 15 be ready to protect your borage 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.