The weather channels are all breathless over the arctic front crossing the country tonight and tomorrow. In the Deep South, we probably don’t need to worry about “Snowzilla” or “Snowmaggedon”. However, much of the Gulf Coast hibiscus growing regions will get many hours of below freezing weather.
Houston is forecast to have two consecutive nights of 8 hours or more below freezing, with temperatures possibly as low as 20F to 24F, depending on which weather channel you watch.
Tropical hibiscus simply die at that temperature. Just putting a sheet or other light cover over tropical plants at 20F is wishful thinking.
Unless the plants are in a greenhouse, or under good cover with additional heat, they will not survive such an extended freeze.
Potted plants are fairly simply, just bring them indoors. Be careful of your back, those pots can be heavy! Hibiscus that are planted in-ground are a problem, because they are not likely to survive a deep freeze.
Since I haven’t had time to setup a temporary greenhouse this year, I resorted to the “shovel solution”. Fortunately, most of my in-ground hibiscus are in old, established beds with good soft soil, so it wasn’t too much trouble to dig up a dozen or so of my favorite hibiscus, put them in pots or garbage bags, and bring them indoors for a couple of days.
Other tropical plants also get the shovel treatment in weather this cold, and four large brugmansia were pruned very short and dug up, as well as a variety of succulents, gingers, etc.
When doing an emergency “dig”, it is normal to lose some of the root system. Before replanting or potting the plants, prune the branches back to at least match the loss of roots.
Prunings, from hibiscus and other tropicals such as brugs, can be cut into short lengths and rooted, so even if the plant doesn’t survive, perhaps some of the cuttings will. In my case, three of my ten-foot tall brugs have now been cut up into dozens of foot-long cuttings, and will hopefully grow into many new plants.