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.

A common way of making a decision about when it's the best time to plant calla lily is to check out the USDA zone info for New Castle.

Planting Calendar for Calla Lily

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

Since calla lily require warm weather it is necessary to wait until after the last frost before you can plant them.

The earliest that you can plant calla lily 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 calla lily and expect a good harvest is probably August. Any later than that and your calla lily may not have a chance to really do well. Starting your calla lily indoors is a great way to get them started a few weeks earlier.

Last Frost Date

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

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for New Castle and it changes from year to year. Since half of the time in New Castle you get a frost after April 15 be ready to protect your calla lily in the event of a surprise late frost.

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.