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.

By looking at the USDA zone info for Waltham it's a good idea to determine when it's possible to plant black eyed susans.

Planting Calendar for Black Eyed Susans

Frost tolerance for black eyed susans:	Not tolerant of frost.
When to plant:	After the last frost.

Black Eyed Susans do not do well in cold weather which tells us that it's necessary to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant black eyed susans in Waltham 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 black eyed susans and expect a good harvest is probably August. Any later than that and your black eyed susans may not have a chance to fully mature. Starting your black eyed susans indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Waltham. In the coldest months of winter you can expect an average low temperature of -10°F.

Keep in mind that USDA zone info for Waltham is an average and the actual date of last frost is different every year. Half of the time in Waltham you get surprised by a frost after April 15 so just be sure to be ready to cover your black eyed susans in the event of a late frost.

USDA Zone Info for Waltham

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Waltham

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