One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of estimating when it's the best time to plant common hollyhock is to examine the USDA zone info for Stillwater.

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 bit earlier in the year than more sensitive plants.

The earliest that you can plant common hollyhock in Stillwater 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. Any later than that and 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 few weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Stillwater. It might get as low as -25°F during the coldest months of winter.

It's important to remember that USDA zone info for Stillwater is not always accurate and the actual date of last frost will vary from year to year. Since half of the time in Stillwater there is a last frost after May 15 be ready to cover your common hollyhock in the event of a surprise late frost.

USDA Zone Info for Stillwater

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 Stillwater

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