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.

You will be able to figure out when it's the best time to plant achimenes by looking at the USDA zone info for Pierre.

Planting Calendar for Achimenes

Frost tolerance for achimenes:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Achimenes require warm weather which means that it's important to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant achimenes in Pierre is May. However, you really should wait until June if you don't want to take any chances.

The last month that you can plant achimenes and expect a good harvest is probably August. If you wait any later than that and your achimenes may not have a chance to grow to maturity. If you are starting your achimenes indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Pierre. In the coldest months of winter you should expect an average low temperature of -25°F.

Remember that USDA zone info for Pierre is an average and the actual date of last frost is different every year. Half of the time in Pierre it frosts late in the year after May 15 so always be ready to cover your achimenes in the event of one of those late frosts.

USDA Zone Info for Pierre

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Pierre

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