One of the best tools that you have as gardeners to help us determine 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 way of making a decision about when to plant hollyhocks is to refer to the USDA zone info for Zone 1b.

Planting Calendar for Hollyhocks

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

Hollyhocks do ok in mild cold which tells us that you can plant them a little earlier in the year than other plants that might not handle the cold.

The earliest that you can plant hollyhocks in Zone 1b is May. However, you really should wait until June if you don't want to take any chances.

The last month that you can plant hollyhocks and expect a good harvest is probably July. You probably don't want to wait any later than that or else 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

On average the last frost has passed is on June 15 in Zone 1b. You should expect an average low temperature of -55°F in the coldest months of winter.

Since the USDA zone info for Zone 1b is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Zone 1b you get a frost after June 15 so make sure that you are ready to cover your hollyhocks in the event of a late frost.

USDA Zone Info for Zone 1b

Here is the info for USDA Zone 1b.

Average Date of Last Frost (spring)	June 15
Average Date of First Frost (fall)	July 15
Lowest Expected Low	-55°F
Highest Expected Low	-50°F

This means that on a really cold year, the coldest it will get is -55°F. On most years you should be prepared to experience lows near -50°F.

Plants to Grow in Zone 1b

You may be interested in your other planting guides for Zone 1b.