The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Gladstone should be looked at to determine when 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 do well in very little cold which tells us that you can plant them slightly earlier in the year than more sensitive plants.

The earliest that you can plant astilbe in Gladstone 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 couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Gladstone. In the coldest months of winter you should expect an average low temperature of -20°F.

Since the USDA zone info for Gladstone is just an average the actual date of last frost will vary from year to year. Half of the time in Gladstone it frosts late in the year after April 15 so always be ready to cover your astilbe in the event of a late frost.

USDA Zone Info for Gladstone

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Gladstone

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