One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant calla lily in Onalaska should be determined by looking at the USDA zone info.

Planting Calendar for Calla Lily

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

It's a bad idea to plant calla lily until after all chance of frost has passed because they require warm weather.

The earliest that you can plant calla lily in Onalaska 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. You probably don't want to wait any later than that or else your calla lily may not have a chance to really do well. If you are starting your calla lily indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Onalaska the average date of last frost happens on May 15. It might get as low as -25°F during the coldest months of winter.

Always keep in mind that USDA zone info for Onalaska is an average and the actual date of last frost changes from year to year. Half of the time in Onalaska there is a last frost after May 15 so be sure to be ready to protect your calla lily in the event of one of those late frosts.

USDA Zone Info for Onalaska

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 Onalaska

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