The USDA Zone info is a great tool for gardeners to help us determine 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.

You should be able to figure out when it's the best time to plant pyrethrum by checking out the USDA zone info for Williamsport.

Planting Calendar for Pyrethrum

Frost tolerance for pyrethrum:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Pyrethrum do ok in a little bit of cold which tells us that you can plant them just a bit earlier in the year than other frost tender plants.

The earliest that you can plant pyrethrum in Williamsport 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 grow to maturity. You can get started a little bit earlier by starting your pyrethrum indoors.

Last Frost Date

The average date of last frost is April 15 in Williamsport. In the coldest months of winter you can expect an average low temperature of -5°F.

Just be sure to remember that USDA zone info for Williamsport may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Williamsport there is a last frost after April 15 so always be ready to protect your pyrethrum if you have a surprise late frost.

USDA Zone Info for Williamsport

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 Williamsport

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