The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Howell should be used to determine when it's a good idea to plant hardy hibiscus.

Planting Calendar for Hardy Hibiscus

Frost tolerance for hardy hibiscus:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Hardy Hibiscus do well in cold which tells us that you can start planting them much earlier than other frost tender plants.

The earliest that you can plant hardy hibiscus in Howell 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 hardy hibiscus and expect a good harvest is probably September. If you wait any later than that and your hardy hibiscus may not have a chance to fully mature. If you are starting your hardy hibiscus indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Howell. You should expect an average low temperature of -10°F in the coldest months of winter.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Howell and it changes from year to year. Half of the time in Howell last frost occurs after April 15 so just be sure to be ready to protect your hardy hibiscus in the event of a late frost.

USDA Zone Info for Howell

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Howell

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