As potted plants, they can be maintained
at indoor temperatures above 60°.They can suffer when grown at temperatures below 60°
for extended periods.
Humidity:
Preferably 50% or
higher; however, they will tolerate lower levels with no harm.
Watering:
Bring soil to a state of visual dryness
between watering.When
watering thoroughly, saturate soil until a little water runs out of the
bottom of the pot.
Fertilizer:
They are moderate feeders so a 1/4
tsp./gallon once a week is a general recommendation.When growth slows in winter, reduce or discontinue feeding.Use a balanced fertilizer i.e. 15-15-15 or a blooming fertilizer
like Pro Gro ‘Grow’ 7-9-5 or Electra 5-10-3.
Pruning:
Prune any time they are too large or
getting leggy.Remember that
they flower on the tips of new growth and pruning will slow down
blooming.
Insects and
Disease:
Hibiscus are susceptible to whitefly and
aphids as well as spider mite when grown under hot dry conditions.They are susceptible to fungal root rots especially during the
winter months under excessive soil moisture and cool conditions.Growing them a little drier helps reduce the problem.
Comments:
Hibiscus are
spectacular flowering plants that require full direct sun, warm
conditions and a balance fertilizer to induce bloom. The long day
length of summer is ideal for flowering. There are many cultivarswhich seem to have varying degrees of ease to bloom.Some, like our old fashioned H. rosa sinensis, seem never to
stop while the double variety H. Ruth Wilcox under our culture is a
shy bloomer.
