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.

In Waterloo you can figure out when it's a good idea to plant hardy hibiscus by checking out the USDA zone info.

Planting Calendar for Hardy Hibiscus

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

Since hardy hibiscus are one of those plants that can tolerate quite a bit of cold weather you can plant them much earlier in the year than other plants that might not handle the cold.

The earliest that you can plant hardy hibiscus in Waterloo 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 few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Waterloo. It might get as low as -10°F during the coldest months of winter.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Waterloo and it changes from year to year. Half of the time in Waterloo there is a last frost after April 15 so always be ready to cover your hardy hibiscus if you have a surprise late frost.

USDA Zone Info for Waterloo

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 Waterloo

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