The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By looking at the USDA zone info for Commerce City it's a good idea to figure out when it's a good idea to plant hollyhocks.

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 some cold which means that you can plant them a little bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant hollyhocks in Commerce City 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. If you wait any later than that and your hollyhocks may not have a chance to fully mature. You can get started a little bit earlier by starting your hollyhocks indoors.

Last Frost Date

The average date of last frost is April 15 in Commerce City. You should expect an average low temperature of -15°F in the coldest months of winter.

Always keep in mind 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 Commerce City and it can change quite a bit from year to year. Half of the time in Commerce City it frosts late in the year after April 15 so always be ready to protect your hollyhocks if you have one of those late frosts.

USDA Zone Info for Commerce City

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 Commerce City

You may be interested in your other planting guides for Commerce City.