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

It's possible to determine when it's the best time to plant calla lily by looking at the USDA zone info for Winterset.

Planting Calendar for Calla Lily

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

It's probably a bad idea to plant calla lily until after the last frost because they are not cold tolerant.

The earliest that you can plant calla lily in Winterset 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. You probably don't want to wait any later than that or else your calla lily may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your calla lily indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Winterset. You should expect an average low temperature of -20°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 Winterset and it will vary from year to year. Half of the time in Winterset you get a frost after April 15 so just be sure to be ready to cover your calla lily if you have a surprise late frost.

USDA Zone Info for Winterset

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Winterset

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