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 earliest that you can plant common hollyhock in Rockville can be estimated by looking at the USDA zone info.

Planting Calendar for Common hollyhock

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

Common hollyhock can survive in a little bit of cold which tells us that you can plant them a little bit earlier in the year than more sensitive plants.

The earliest that you can plant common hollyhock 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 common hollyhock and expect a good harvest is probably September. You probably don't want to wait any later than that or else your common hollyhock may not have a chance to grow to maturity. Starting your common hollyhock indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Rockville. You should expect an average low temperature of 0°F in the coldest months of winter.

Since the USDA zone info for Rockville is just an average the actual date of last frost will vary from year to year. Since half of the time in Rockville last frost occurs after April 15 be ready to protect your common hollyhock if you have a 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.