The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Cincinnati should be reffered to in order to determine when it's possible 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 can survive in a little bit of cold which tells us that you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant pyrethrum in Cincinnati is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant pyrethrum and expect a good harvest is probably September. You probably don't want to wait any later than that or else your pyrethrum may not have a chance to fully mature. 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

The average date of last frost is April 15 in Cincinnati. It might get as low as -5°F during the coldest months of winter.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Cincinnati and it can change quite a bit from year to year. Since half of the time in Cincinnati last frost occurs after April 15 be ready to cover your pyrethrum in the event of a surprise late frost.

USDA Zone Info for Cincinnati

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Cincinnati

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