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When to Plant Common hollyhock in Grinnell, IA

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.

A common way of making a decision about when it's a good idea to plant common hollyhock is to consult the USDA zone info for Grinnell.


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 some cold which means that you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant common hollyhock
Possibly ok, but a risky time to plant common hollyhock
Probably not a good time to plant common hollyhock

The earliest that you can plant common hollyhock in Grinnell 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. You probably don't want to wait any later than that or else 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 is on April 15 in Grinnell. In the coldest months of winter you can expect an average low temperature of -20°F.

Keep in mind that USDA zone info for Grinnell is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Grinnell you get surprised by a frost after April 15 so just be sure to be ready to protect your common hollyhock in the event of a surprise late frost.

USDA Zone Info for Grinnell

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-20°F
Highest Expected Low-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Grinnell

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