The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first chance to plant common hollyhock in Merrillville should 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 do well in moderate cold which tells us that you can get them planted earlier than other frost tender plants.

The earliest that you can plant common hollyhock in Merrillville 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. Any later than that and your common hollyhock may not have a chance to fully mature. You can get started a few weeks earlier by starting your common hollyhock indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Merrillville. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Merrillville is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Merrillville it frosts late in the year after April 15 be ready to cover your common hollyhock if you have a surprise late frost.

USDA Zone Info for Merrillville

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 Merrillville

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