One of the first steps you take when you are figuring out your gardening schedule is find your 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.

One way of figuring out when it's the best time to plant astilbe is to check out the USDA zone info for Groton.

Planting Calendar for Astilbe

Frost tolerance for astilbe:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

You can plant astilbe slightly earlier in the year because they do ok in moderate cold.

The earliest that you can plant astilbe in Groton 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 astilbe and expect a good harvest is probably August. If you wait any later than that and your astilbe may not have a chance to grow to maturity. Starting your astilbe indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Always keep in mind that USDA zone info for Groton is an average and the actual date of last frost changes from year to year. Since half of the time in Groton it frosts late in the year after April 15 be ready to protect your astilbe 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.