1. Every fall the leaves on my
Gardenia and Hibiscus
shrubs turn yellow and drop. What could cause this?
In fall and spring, when night temperatures are cool and days are warm, it
is not uncommon for some leaves to turn yellow and drop. There is no
treatment or prevention for this. If yellow leaves and leaf drop occur at
other times of the year, it is a sign of stress resulting from water
stress, improper fertilization, root disorders, nematodes, or misuse of
chemicals. See Gardenias
at a Glance, Growing
Gardenias in Florida, and
Hibiscus in Florida.
2. The flower buds on my
Hibiscus and Gardenia plant
drop before they open. What could the problem be?
Bud drop is
often a problem with both of these plants and can indicate an insect
problem, cultural/environmental problem, or a characteristic of that
variety. Insects called thrips can damage the unopened bud. These
may go undetected until considerable damage has occurred and the buds
on Landscape Plants. Too much or too little fertilizer and/or water can
stress the plant resulting in bud drop. Nematodes can attack the
root system reducing the plant's ability to take up water and nutrients.
Some varieties of Hibiscus, especially doubles, are characterized by
premature bud drop. Some varieties bloom well during one period of the
year and consistently drop their buds at all other
Hibiscus flower bud drop
is a common problem usually caused by a midge. Peel back the petals
of a flower that has, or is about to fall off. Look for a very small
yellow worm-like insect. It is smaller than an inch worm and will
hop when disturbed. This is the gall midge larva (Contarina
maculipennis). The adults lay larvae on the plant. The
larvae develop in the bud, then drop to the ground to pupate. There are no official
recommendations for control.
Should I mulch my plants?
is considered a beneficial practice for all ornamental plants. Mulching
conserves soil moisture, insulates the soil (keeps it cooler in summer and
warmer in winter) and suppresses weeds. Organic mulches such as shredded
wood, pine needles, or oak leaves are preferred to inorganic mulches such
as pebbles and stone. The desired depth of the mulch is 2 to 3 inches
after settling. The area immediately around the stem of the plant
should be left free of mulch.
leaves on my plants are turning yellow with black spots. What causes this
problem, and what can I do about it?
sounds like your plant may be suffering from a leaf spot fungi. To treat the
problem, you should remove affected leaves and apply a fungicide. Be sure to
follow all safety precautions and label recommendations.
To find out which fungicides will work best on your plants, contact or visit
your County Extension Office.
can I plant in my yard?
Native Florida Plants for Home Landscapes.
For landscaping information, read
Principles of Landscape Design
online guide to shade tree maintenance. For general information about
home landscapes and gardens, visit the
Lawn & Garden section of the Solutions For Your Life website.
plants have a high salt and wind tolerance?
A number of plants will tolerate
coastal conditions. Read our publications,
Salt-Tolerant Plants for Florida
Native Landscape Plants for South Florida.