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.

By using the USDA zone info for Madison it's possible to figure out when it's the best time 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.

You can plant pyrethrum a little earlier in the year because they are moderately cold tolerant.

The earliest that you can plant pyrethrum in Madison 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 few weeks earlier.

Last Frost Date

In Madison 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.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Madison and it is different every year. Half of the time in Madison it frosts late in the year after May 15 so always be ready to protect your pyrethrum in the event of a surprise late frost.

USDA Zone Info for Madison

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 Madison

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