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 best time to plant alternanthera in New Castle can be estimated by looking at the USDA zone info.

Planting Calendar for Alternanthera

Frost tolerance for alternanthera:	Not tolerant of frost.
When to plant:	After the last frost.

Since alternanthera require warm weather you have to wait until after the last frost before you can plant them.

The earliest that you can plant alternanthera in New Castle is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant alternanthera and expect a good harvest is probably August. If you wait any later than that and your alternanthera may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your alternanthera indoors.

Last Frost Date

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

Just be sure to remember that USDA zone info for New Castle may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in New Castle it frosts late in the year after April 15 so always be ready to protect your alternanthera 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.