One of the best tools that you have as gardeners to help us figure out 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.

One way of getting a good idea when it's possible to plant calla lily is to examine the USDA zone info for Pittsburgh.

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 important to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant calla lily in Pittsburgh 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. Any later than that and 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

In Pittsburgh the average date of last frost happens on April 15. You can expect an average low temperature of -5°F in the coldest months of winter.

Remember that USDA zone info for Pittsburgh is not always accurate and the actual date of last frost is different every year. Since half of the time in Pittsburgh you get surprised by a frost after April 15 be ready to cover your calla lily in the event of a late frost.

USDA Zone Info for Pittsburgh

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Pittsburgh

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