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.

One way of determining when you can plant calla lily is to use the USDA zone info for Holmen.

Planting Calendar for Calla Lily

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

Calla Lily require warm weather which tells us that it's necessary to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant calla lily in Holmen is May. However, you really should wait until June 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. If you wait any later than that and your calla lily may not have a chance to fully mature. Starting your calla lily indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Holmen the average date of last frost happens on May 15. You can expect an average low temperature of -25°F in the coldest months of winter.

It's important to remember that USDA zone info for Holmen may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Since half of the time in Holmen last frost occurs after May 15 be ready to cover your calla lily if you have a late frost.

USDA Zone Info for Holmen

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Holmen

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