Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By looking at the USDA zone info for Minot you should be able 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 do ok in moderate cold which tells us that you can start planting them slightly earlier than other frost tender plants.

The earliest that you can plant astilbe in Minot is April. However, you really should wait until May 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 few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on May 15 in Minot. It might get as low as -30°F during the coldest months of winter.

Since the USDA zone info for Minot may not be accurate from year to year the actual date of last frost is different every year. Half of the time in Minot last frost occurs after May 15 so just be sure to be ready to cover your astilbe in the event of a late frost.

USDA Zone Info for Minot

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Minot

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