Growing Tropical Hibiscus in the Desert is Not Easy

Tropical hibiscus growing in Las Vegas Nevada in the Mojave Desert.

Q. I’m forwarding pictures of my existing hibiscus that turned
brown this past winter.  It actually
looks like there’s some growth on two of them but the others look pretty
grim.  Should I give them a chance to
grow or start again?  Also, if I do
attempt to let these live should I trim them to the ground?

A. It looks like your hibiscus really got hammered this past
winter. And this winter was not really that cold. These are most likely
tropical hibiscus.

Hibiscus is a common name for a
number of different plants with different attributes. These range from the
tropical hibiscus to plants that we call hibiscus but are winter hardy in our
climate.

Roselle hibiscus growing on MoCa Farm in the Philippines.

Your hibiscus was probably one
of the tropical or subtropical types. Judging from your picture, the soil looks
like it was hardly improved at all and rocks are strewn along the surface.
These issues must be addressed if you expect these plants to do well at all in
the future.

They need a lot of soil
amendment added at the time of planting. Even though they can handle a lot of
heat, they cannot handle the extreme heat and low humidity of unshaded south
and western microclimates of the Mojave Desert.

They will look best protected
from late afternoon sun and the soil covered with organic mulch. They will also
do better if surrounded with plants that need moist, organic soils as well.

I would cut them to the ground in
the spring, fertilize and water them and see if they will come back. Pull the
rock away from them and put down a layer of compost about one inch thick
followed by three inches of wood mulch on the surface. Keep the wood mulch away
from the stems of the plants by about 12 inches.

In the future you will treat
them like herbaceous perennials; let them grow during the warm and hot months
and cut them to the ground after they freeze back. Pile mulch around their base
that is three to four inches deep. This may be enough to minimize winter cold
damage.

Here is an article we (MoCa Farm) wrote for Food Tank on the growing and culinary use of Roselle hibiscus in the Philippines. http://foodtank.com/news/2014/02/a-love-affair-with-roselle