One of the first steps you take when you are making a decision about your gardening schedule is find your 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 Vernon Hills you can figure out when it's a good idea to plant hollyhocks by looking at 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.

Hollyhocks do ok in a little bit of cold which means that you can plant them just a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant hollyhocks in Vernon Hills 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 hollyhocks and expect a good harvest is probably September. Any later than that and your hollyhocks may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your hollyhocks indoors.

Last Frost Date

In Vernon Hills the average date of last frost happens on April 15. You can expect an average low temperature of -15°F in the coldest months of winter.

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 Vernon Hills and it will vary from year to year. Since half of the time in Vernon Hills it frosts late in the year after April 15 be ready to cover your hollyhocks if you have a late frost.

USDA Zone Info for Vernon Hills

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Vernon Hills

You may be interested in your other planting guides for Vernon Hills.