One of the best tools that you have as gardeners to help us determine 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.

The first opportunity to plant astilbe in East Alton should be determined by looking at 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 do ok in some cold which tells us that you can plant them just a tiny bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant astilbe in East Alton 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. You probably don't want to wait any later than that or else your astilbe may not have a chance to fully mature. Starting your astilbe 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 East Alton. In the coldest months of winter you should expect an average low temperature of -10°F.

Since the USDA zone info for East Alton is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in East Alton it frosts late in the year after April 15 so be sure to be ready to protect your astilbe if you have one of those late frosts.

USDA Zone Info for East Alton

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 East Alton

You may be interested in your other planting guides for East Alton.