The USDA Zone info is a great tool for gardeners to help us estimate 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.

You should be able to estimate when to plant twinspur by referring to the USDA zone info for Groton.

Planting Calendar for Twinspur

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

Twinspur do well in moderate cold which tells us that you can get them planted earlier than other frost tender plants.

The earliest that you can plant twinspur in Groton is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant twinspur and expect a good harvest is probably September. Any later than that and your twinspur may not have a chance to grow to maturity. Starting your twinspur indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Groton. It might get as low as -5°F during the coldest months of winter.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Groton and it is different every year. Half of the time in Groton you get a frost after April 15 so just be sure to be ready to cover your twinspur if you have a late frost.

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.