Before planting it is a good idea to find your USDA Zone info to determine your garden 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 the best time to plant pyrethrum is to consult the USDA zone info for Rhinelander.

Planting Calendar for Pyrethrum

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

Since pyrethrum are moderately cold tolerant you can plant them a little bit earlier in the year than other frost tender plants.

The earliest that you can plant pyrethrum in Rhinelander 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. You probably don't want to wait any later than that or else your pyrethrum may not have a chance to fully mature. You can get started a few weeks earlier by starting your pyrethrum indoors.

Last Frost Date

The average date of last frost is May 15 in Rhinelander. It might get as low as -30°F during the coldest months of winter.

Keep in mind that USDA zone info for Rhinelander may not be accurate from year to year and the actual date of last frost is different every year. Since half of the time in Rhinelander there is a last frost after May 15 be ready to cover your pyrethrum if you have a surprise late frost.

USDA Zone Info for Rhinelander

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 Rhinelander

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