One of the first steps you take when you are getting a good idea 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 can determine when you can plant astilbe in Waltham by reviewing the USDA zone info.

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.

Since astilbe are one of those plants that can tolerate a tiny bit of cold weather you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant astilbe in Waltham 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. You can get started a couple of weeks earlier by starting your astilbe indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Waltham. It might get as low as -10°F during the coldest months of winter.

Remember that USDA zone info for Waltham is just an average and the actual date of last frost will vary from year to year. Since half of the time in Waltham you get a frost after April 15 be ready to cover your astilbe if you have a surprise 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.