One of the best tools that you have as gardeners to help us figure out 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.

A way of figuring out when to plant common hollyhock is to look at the USDA zone info for Dover.

Planting Calendar for Common hollyhock

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

Since common hollyhock are moderately cold tolerant you can plant them a little earlier in the year than other frost tender plants.

The earliest that you can plant common hollyhock in Dover 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. If you wait any later than that and your common hollyhock may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your common hollyhock indoors.

Last Frost Date

The average date of last frost is April 15 in Dover. You can expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for Dover may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Dover it frosts late in the year after April 15 so just be sure to be ready to protect your common hollyhock if you have one of those late frosts.

USDA Zone Info for Dover

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Dover

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