The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of estimating when it's the best time to plant common hollyhock is to look at the USDA zone info for Amsterdam.

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 tells us that you can plant them a little bit earlier than other frost tender plants.

The earliest that you can plant common hollyhock in Amsterdam 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 really do well. Starting your common hollyhock indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Amsterdam. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Amsterdam is not always accurate the actual date of last frost will vary from year to year. Since half of the time in Amsterdam there is a last frost after April 15 be ready to protect your common hollyhock if you have one of those late frosts.

USDA Zone Info for Amsterdam

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Amsterdam

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