The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Rockville can be reviewed to figure out 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 means that you really should wait until it warms up after the last frost before you can plant them.

The earliest that you can plant calla lily in Rockville 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. If you wait any later than that and your calla lily may not have a chance to really do well. You can get started a few weeks earlier by starting your calla lily indoors.

Last Frost Date

In Rockville the average date of last frost happens on April 15. It might get as low as 0°F during the coldest months of winter.

Since the USDA zone info for Rockville is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Rockville you get a frost after April 15 be ready to cover your calla lily if you have a surprise late frost.

USDA Zone Info for Rockville

Here is the info for USDA Zone 7a.

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

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

Plants to Grow in Rockville

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