One of the first steps you take when you are estimating your gardening schedule is find your 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 first opportunity to plant common hollyhock in Portsmouth can be figured out by using 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 are moderately cold tolerant which means that you can plant them earlier than other plants that might not handle the cold.

The earliest that you can plant common hollyhock in Portsmouth 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 Portsmouth. You should expect an average low temperature of -10°F in the coldest months of winter.

It's important to remember that USDA zone info for Portsmouth may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in Portsmouth last frost occurs after April 15 so be sure to be ready to cover your common hollyhock in the event of a late frost.

USDA Zone Info for Portsmouth

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 Portsmouth

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