One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's possible to figure out when it's the best time to plant anchusa by reviewing the USDA zone info for Watertown.

Planting Calendar for Anchusa

Frost tolerance for anchusa:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since anchusa are very cold tolerant you can plant them much earlier in the year than plants that are more sensitive to the cold.

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

Last Frost Date

The average date of last frost is May 15 in Watertown. It might get as low as -25°F during the coldest months of winter.

Since the USDA zone info for Watertown is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Watertown there is a last frost after May 15 be ready to protect your anchusa if you have a surprise late frost.

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.