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.

You will be able to determine when it's the best time to plant common hollyhock by referring to the USDA zone info for Isanti.

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 one of those plants that can tolerate a little bit of cold weather you can plant them a little bit earlier in the year than other frost tender plants.

The earliest that you can plant common hollyhock in Isanti 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 little bit earlier.

Last Frost Date

In Isanti the average date of last frost happens on May 15. In the coldest months of winter you can expect an average low temperature of -30°F.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Isanti and it changes from year to year. Since half of the time in Isanti 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 Isanti

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Isanti

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