One of the best tools that you have as gardeners to help us estimate 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 Duluth you can figure out when it's a good idea to plant hollyhocks by referring to the USDA zone info.

Planting Calendar for Hollyhocks

Frost tolerance for hollyhocks:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since hollyhocks are moderately cold tolerant you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant hollyhocks in Duluth 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 hollyhocks and expect a good harvest is probably August. Any later than that and your hollyhocks may not have a chance to really do well. Starting your hollyhocks indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Duluth 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.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Duluth and it changes from year to year. Half of the time in Duluth last frost occurs after May 15 so make sure that you are ready to protect your hollyhocks if you have a late frost.

USDA Zone Info for Duluth

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 Duluth

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