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 first chance to plant pyrethrum in Grand Forks can be determined by looking at the USDA zone info.

Planting Calendar for Pyrethrum

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

Pyrethrum do ok in mild cold which means that you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant pyrethrum in Grand Forks 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. Any later than that and your pyrethrum may not have a chance to really do well. If you are starting your pyrethrum 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 Grand Forks. You should expect an average low temperature of -30°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Grand Forks is an average and the actual date of last frost is different every year. Half of the time in Grand Forks there is a last frost after May 15 so make sure that you are ready to protect your pyrethrum in the event of a late frost.

USDA Zone Info for Grand Forks

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 Grand Forks

You may be interested in your other planting guides for Grand Forks.