One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's a good idea to figure out when it's the best time to plant calla lily by reviewing the USDA zone info for Bismarck.

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 Bismarck 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 grow to maturity. You can get started a little bit earlier by starting your calla lily indoors.

Last Frost Date

The average date of last frost is May 15 in Bismarck. You can expect an average low temperature of -30°F in the coldest months of winter.

Since the USDA zone info for Bismarck may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in Bismarck it frosts late in the year after May 15 be ready to protect your calla lily in the event of a late frost.

USDA Zone Info for Bismarck

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 Bismarck

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