One of the first steps you take when you are estimating your gardening schedule is find your 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.

In Marshall you can determine when you can plant pyrethrum 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.

You can plant pyrethrum a little earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant pyrethrum in Marshall 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 fully mature. You can get started a couple of weeks earlier by starting your pyrethrum indoors.

Last Frost Date

The average date of last frost is May 15 in Marshall. It might get as low as -25°F during the coldest months of winter.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Marshall and it will vary from year to year. Half of the time in Marshall there is a last frost after May 15 so just be sure to be ready to cover your pyrethrum in the event of a late frost.

USDA Zone Info for Marshall

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 Marshall

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