One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By referring to the USDA zone info for Mandan you should be able to figure out when it's possible to plant oxalis.

Planting Calendar for Oxalis

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

Oxalis do not do well in cold weather which means that you need to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant oxalis 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 oxalis and expect a good harvest is probably August. Any later than that and your oxalis may not have a chance to really do well. Starting your oxalis indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Mandan the average date of last frost happens on May 15. In the coldest months of winter you can expect an average low temperature of -30°F.

Since the USDA zone info for Mandan is 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 oxalis if you have a late frost.

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.