One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to figure out when you can plant heliotrope by referring to the USDA zone info for Groton.

Planting Calendar for Heliotrope

Frost tolerance for heliotrope:	Not tolerant of frost.
When to plant:	After the last frost has passed.

You really shouldn't plant heliotrope until after the last frost has passed because they do not do well in cold weather.

The earliest that you can plant heliotrope in Groton 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 heliotrope and expect a good harvest is probably August. You probably don't want to wait any later than that or else your heliotrope may not have a chance to fully mature. You can get started a few weeks earlier by starting your heliotrope indoors.

Last Frost Date

The average date of last frost is April 15 in Groton. You can expect an average low temperature of -5°F in the coldest months of winter.

Remember that USDA zone info for Groton may not be accurate from year to year and the actual date of last frost is different every year. Half of the time in Groton last frost occurs after April 15 so make sure that you are ready to cover your heliotrope in the event of one of those late frosts.

USDA Zone Info for Groton

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Groton

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