The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of determining when it's possible to plant marigold is to use the USDA zone info for Sioux Falls.

Planting Calendar for Marigold

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

Since marigold are not cold tolerant you must wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant marigold in Sioux Falls 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 marigold and expect a good harvest is probably August. Any later than that and your marigold may not have a chance to fully mature. Starting your marigold indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Sioux Falls the average date of last frost happens on May 15. In the coldest months of winter you can expect an average low temperature of -25°F.

Since the USDA zone info for Sioux Falls is an average the actual date of last frost is different every year. Half of the time in Sioux Falls you get a frost after May 15 so make sure that you are prepared to protect your marigold in the event of a surprise late frost.

USDA Zone Info for Sioux Falls

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 Sioux Falls

You may be interested in your other planting guides for Sioux Falls.