One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

You can determine when you can plant astilbe in New Castle 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.

Astilbe can survive in very little cold which means that you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant astilbe in New Castle 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 really do well. Starting your astilbe indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In New Castle the average date of last frost happens on April 15. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for New Castle is an average the actual date of last frost is different every year. Since half of the time in New Castle there is a last frost after April 15 be ready to cover your astilbe in the event of one of those late frosts.

USDA Zone Info for New Castle

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 New Castle

You may be interested in your other planting guides for New Castle.