The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant pyrethrum in New Castle can be figured out by looking at 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 bit earlier in the year because they are moderately cold tolerant.

The earliest that you can plant pyrethrum in New Castle 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. If you are starting your pyrethrum indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

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

It's important to remember that USDA zone info for New Castle is just an average and the actual date of last frost changes from year to year. Half of the time in New Castle you get a frost after April 15 so just be sure to be ready to cover your pyrethrum if you have one of those late frosts.

USDA Zone Info for New Castle

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 New Castle

You may be interested in your other planting guides for New Castle.