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.

In New Ulm you can estimate when to plant common hollyhock by referring to 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.

You can plant common hollyhock a bit earlier in the year because they are moderately cold tolerant.

The earliest that you can plant common hollyhock in New Ulm is March. However, you really should wait until April 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 August. You probably don't want to wait any later than that or else your common hollyhock may not have a chance to fully mature. Starting your common hollyhock indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on May 15 in New Ulm. In the coldest months of winter you should expect an average low temperature of -25°F.

Remember that USDA zone info for New Ulm is an average and the actual date of last frost will vary from year to year. Half of the time in New Ulm it frosts late in the year after May 15 so make sure that you are prepared to protect your common hollyhock if you have a late frost.

USDA Zone Info for New Ulm

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in New Ulm

You may be interested in your other planting guides for New Ulm.