When to Plant Hardy Hibiscus in Merrillville, IN

Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant hardy hibiscus in Merrillville can be estimated by reviewing 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.

Hardy Hibiscus can survive in a bit of cold which tells us that you can plant them a lot earlier in the year than other frost tender plants.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant hardy hibiscus
Possibly ok, but a risky time to plant hardy hibiscus
Probably not a good time to plant hardy hibiscus

The earliest that you can plant hardy hibiscus in Merrillville 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 grow to maturity. 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

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

It's important to remember that USDA zone info for Merrillville may not be accurate from year to year and the actual date of last frost is different every year. Since half of the time in Merrillville last frost occurs after April 15 be ready to cover your hardy hibiscus in the event of a surprise late frost.

USDA Zone Info for Merrillville

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 Merrillville

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