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.

The USDA zone info for Rockville can be reviewed to estimate when it's a good idea to plant coral bells.

Planting Calendar for Coral Bells

Frost tolerance for coral bells:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Coral Bells can survive in some cold which means that you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant coral bells in Rockville is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant coral bells and expect a good harvest is probably September. You probably don't want to wait any later than that or else your coral bells may not have a chance to grow to maturity. If you are starting your coral bells indoors then you might be able to get away with starting them a few weeks earlier.

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.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Rockville and it will vary from year to year. Half of the time in Rockville you get a frost after April 15 so be sure to be ready to cover your coral bells if you have one of those late frosts.

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.