One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can figure out when you can plant pyrethrum in Columbus by referring to 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 bit earlier in the year because they are moderately cold tolerant.

The earliest that you can plant pyrethrum in Columbus 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 grow to maturity. You can get started a couple of weeks earlier by starting your pyrethrum indoors.

Last Frost Date

In Columbus the average date of last frost happens on March 15. In the coldest months of winter you should expect an average low temperature of 15°F.

Since the USDA zone info for Columbus may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Columbus you get surprised by a frost after March 15 be ready to cover your pyrethrum in the event of a late frost.

USDA Zone Info for Columbus

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in Columbus

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