One of the first steps you take when you are estimating your gardening schedule is find your 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.

The USDA zone info for Waterloo can be looked at to estimate when it's a good idea to plant calla lily.

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.

Calla Lily are not cold tolerant which tells us that you must wait until it warms up after the last frost before you can plant them.

The earliest that you can plant calla lily in Waterloo 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. 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

The average date of last frost is April 15 in Waterloo. It might get as low as -10°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Waterloo is just an average and the actual date of last frost changes from year to year. Since half of the time in Waterloo last frost occurs after April 15 be ready to cover your calla lily if you have a surprise late frost.

USDA Zone Info for Waterloo

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Waterloo

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