One of the first steps you take when you are getting a good idea your gardening schedule is find your 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 estimate when it's the best time to plant pyrethrum in Swarthmore 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 tend to make it in mild cold which means 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 Swarthmore 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. You can get started a couple of weeks earlier by starting your pyrethrum indoors.

Last Frost Date

The average date of last frost is April 15 in Swarthmore. You should expect an average low temperature of 0°F in the coldest months of winter.

Keep in mind that USDA zone info for Swarthmore may not be accurate from year to year and the actual date of last frost is different every year. Since half of the time in Swarthmore there is a last frost after April 15 be ready to protect your pyrethrum if you have one of those late frosts.

USDA Zone Info for Swarthmore

Here is the info for USDA Zone 7a.

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

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

Plants to Grow in Swarthmore

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