Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The best time to plant pyrethrum in Keene can be determined by reviewing 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.

Pyrethrum do well in moderate cold which tells us that you can plant them earlier than other frost tender plants.

The earliest that you can plant pyrethrum in Keene 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. Any later than that and your pyrethrum may not have a chance to really do well. You can get started a little bit earlier by starting your pyrethrum indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Keene. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Keene is not always accurate the actual date of last frost changes from year to year. Half of the time in Keene you get surprised by a frost after April 15 so just be sure to be ready to cover your pyrethrum in the event of a surprise late frost.

USDA Zone Info for Keene

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°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 -10°F.

Plants to Grow in Keene

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