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.

You can estimate when it's the best time to plant achimenes in Mandan by reviewing the USDA zone info.

Planting Calendar for Achimenes

Frost tolerance for achimenes:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Achimenes do not do well in cold weather which tells us that it is important to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant achimenes in Mandan 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. Any later than that and your achimenes may not have a chance to fully mature. If you are starting your achimenes indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Mandan. In the coldest months of winter you should expect an average low temperature of -30°F.

Since the USDA zone info for Mandan is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Mandan you get a frost after May 15 be ready to cover your achimenes if you have one of those late frosts.

USDA Zone Info for Mandan

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 Mandan

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