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.

The best time to plant hibiscus in Merrill can be determined by using the USDA zone info.

Planting Calendar for Hibiscus

Frost tolerance for hibiscus:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Hibiscus are not cold tolerant which tells us that it is important to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant hibiscus in Merrill 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 hibiscus and expect a good harvest is probably August. Any later than that and your hibiscus may not have a chance to really do well. If you are starting your hibiscus indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Merrill the average date of last frost happens on May 15. You can expect an average low temperature of -30°F in the coldest months of winter.

Since the USDA zone info for Merrill is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Merrill you get surprised by a frost after May 15 so be sure to be ready to protect your hibiscus if you have a late frost.

USDA Zone Info for Merrill

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Merrill

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