One of the first steps you take when you are determining 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.

In Tucson you can estimate when you can plant calla lily 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 probably not a good idea to plant calla lily until after the last frost has passed because they require warm weather.

The earliest that you can plant calla lily in Tucson is March. However, you really should wait until April 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 September. If you wait any later than that and your calla lily may not have a chance to grow to maturity. If you are starting your calla lily indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost has passed is on February 15 in Tucson. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Tucson is just an average the actual date of last frost will vary from year to year. Since half of the time in Tucson last frost occurs after February 15 be ready to protect your calla lily in the event of one of those late frosts.

USDA Zone Info for Tucson

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°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 30°F.

Plants to Grow in Tucson

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