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.

You can estimate when you can plant calliopsis in Rockville by using the USDA zone info.

Planting Calendar for Calliopsis

Frost tolerance for calliopsis:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

You should not plant calliopsis until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant calliopsis 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 calliopsis and expect a good harvest is probably August. You probably don't want to wait any later than that or else your calliopsis may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your calliopsis 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.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Rockville and it is different every year. Since half of the time in Rockville it frosts late in the year after April 15 be ready to cover your calliopsis 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.