Garden News: Hardy hibiscus thrive in south La.

With the unusually cold weather we had in south Louisiana this winter, a good portion of our tropical hibiscuses that normally make it through the winter have been lost.

As people begin replacing lost landscape plants, LSU AgCenter horticulturists suggest considering hardy hibiscuses as replacements for some of the lost tropicals.

The AgCenter is continuing a long-term evaluation trial of hardy hibiscus, primarily Hibiscus moscheutos, at the Hammond Research Station.

“These are what we typically refer to as the ‘dinner plate’ hibiscus that sometimes goes by the old variety name, Disco Belle,” says horticulturist Allen Owings.

Native to roadside ditches around Louisiana, these are one of the species of hibiscus called rose mallow or marsh hibiscus.

One of the outstanding groups of these hibiscuses is the Luna series, which have been designated Louisiana Super Plants. Flower colors include red, rose, white and pink swirl. Luna Pink Swirl seems to be a favorite variety.

They feature 7- to 8-inch flowers on dwarf, compact growing plants. Plants branch well and reach heights of only 36 inches with a similar spread. Luna hibiscus performs best in full sun and starts blooming in late spring and continues until mid-September.

These plants are well-adapted to a wide range of soil types, and drainage is not important. Luna hibiscus can be used in containers or in landscape beds.

You asked

I got a basket of tulips for Easter. They are dead now. Is it OK to wrap them up in tin foil and store in refrigerator until December to plant? Grace

Forcing tulips and other spring bulbs in pots takes a lot out of them, and we generally just discard them when flowering is finished. Exceptions would be bulbs that have a good chance of thriving in our climate and blooming again. Unfortunately, tulips do not grow well or reliably rebloom here. So just discard the tulip bulbs. — Dan Gill, LSU AgCenter horticulturist

Can you please recommend a good chemical-free fertilizer? Robin

A wide variety of organic fertilizer materials include blood meal, bone meal, cottonseed meal, manure, lime, rock phosphate, green sand, kelp/seaweed and guano. You will also find blended organic fertilizers available at your local nurseries. Have your soil tested so you will know what minerals are in short supply in your soil. Contact your parish LSU AgCenter office for information on doing this. — Dan Gill

Got a gardening question? Write to GardenNews@agcenter.lsu.edu.