One of the best tools that you have as gardeners to help us estimate 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 should be able to figure out when it's the best time to plant flax by referring to the USDA zone info for Sioux Falls.

Planting Calendar for Flax

Frost tolerance for flax:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Flax are one of those plants that can tolerate a little bit of cold weather which means that you can plant them a little bit earlier than more sensitive plants.

The earliest that you can plant flax in Sioux Falls is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant flax and expect a good harvest is probably August. You probably don't want to wait any later than that or else your flax may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your flax indoors.

Last Frost Date

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

Keep in mind that USDA zone info for Sioux Falls may not be accurate from year to year and the actual date of last frost is different every year. Half of the time in Sioux Falls you get surprised by a frost after May 15 so make sure that you are ready to protect your flax 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.