Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Bismarck can be read to determine when it's a good idea to plant pyrethrum.

Planting Calendar for Pyrethrum

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

Pyrethrum do well in moderate cold which means that you can plant them earlier than more sensitive plants.

The earliest that you can plant pyrethrum in Bismarck 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 pyrethrum and expect a good harvest is probably August. If you wait any later than that and your pyrethrum may not have a chance to grow to maturity. If you are starting your pyrethrum indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on May 15 in Bismarck. In the coldest months of winter you can expect an average low temperature of -30°F.

Always keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Bismarck and it is different every year. Since half of the time in Bismarck there is a last frost after May 15 be ready to cover your pyrethrum if you have a late frost.

USDA Zone Info for Bismarck

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 Bismarck

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