Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

One way of determining when it's a good idea to plant calla lily is to use the USDA zone info for Duluth.

Planting Calendar for Calla Lily

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

Since calla lily are not cold tolerant it is important to wait until after the last frost before you can plant them.

The earliest that you can plant calla lily in Duluth 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. Any later than that and 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 Duluth the average date of last frost happens on May 15. In the coldest months of winter you can expect an average low temperature of -30°F.

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 Duluth and it can change quite a bit from year to year. Half of the time in Duluth it frosts late in the year after May 15 so just be sure to be ready to protect your calla lily if you have a late frost.

USDA Zone Info for Duluth

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Duluth

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