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

By checking out the USDA zone info for Olney it's a good idea to determine when it's possible to plant astilbe.

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 tend to make it in mild cold which tells us that you can plant them slightly earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant astilbe in Olney 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. 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 little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Olney. In the coldest months of winter you should expect an average low temperature of -10°F.

Remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Olney and it is different every year. Half of the time in Olney you get surprised by a frost after April 15 so be sure to be ready to cover your astilbe if you have a surprise late frost.

USDA Zone Info for Olney

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 Olney

You may be interested in your other planting guides for Olney.