Gardenia
Gardenias are named after Alexander Garden a Charleston, SC colonial physician. They are members of the Rubiaceae family. They originated in Japan and China.
Gardenias will grow to between 2′ and 6′ depending on which variety you have and how much sun it receives.
According to UF Extension gardenias can grow in sun, shade or any where in between. I have yet to hear of anyone successfully growing gardenias in the sun down here. They thrive in shade to part shade. They also recommend fertilizing three times a year in Feb, Mar, and Sept. I’m finding one application in Feb. or March works well for me.
I have one gardenia planted in a dry area of my yard, another on the edge of the swale garden. Neither minds the dry or damp conditions so I don’t think they are particular about watering.
Yellowing leaves may occur because of nutrient deficiencies related to our very basic ph soil. UF Extension recommends acidifying the soil. I purchased some iron granules for lawns and scattered them through all the gardens this spring. You likely want to add some iron and then fertilize regularly. Gardenias are heavy feeders.
As with all flowering shrubs, prune after the plant is done flowering. Pruning done after October will reduce spring flowering.
Most cases of Gardenia suicide can be attributed to nematodes, a soil born root eater. Gardenias are highly susceptible to nematodes. There is nothing you can do. The plant is either grown on resistant root stock or not. Wilting and rapid death will follow if the plant is attacked by nematodes. Gardenias need to be grown on South African Gardenia thunbergia root stock to be protected.
When planting your gardenia add some peat moss to soil and around the area, gardenias prefer more acid soil than is usually found around here.
Watch for spider mites, white flies, and scale. All can be treated by washing off or spraying with orange oil.
Sooty mold usually caused by aphids, just wash it off with soapy water.
More information:
UF Extension, Gardenias
Clemson University Extension, Gardenias
5 Responses to 'Gardenia'
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This plant doesn’t mind the cold at all and often grows in much colder climates than Houston.
admin
7 Jan 08 at 1:58 pm
I’m finding these guys either commit suicide at a young age or just grow forever with little trouble. If one dies on your try another.
They are heavy feeders fertilize often.
ljmacphee
25 Aug 08 at 12:17 pm
The ones that survived infancy are doing great. Flowers started to appear in February.
Someone recently told me that her 12 year old gardenias just up and died last winter. So I guess getting them through infancy isn’t a guarantee of success.
ljmacphee
25 Mar 09 at 9:18 pm
These are still doing ok.
Both of the remaining ones got scraggly and lost a great deal of leaves during the summer drought, but they toughed it out. I’m expecting a full recovery now that it is raining again.
timestocome
9 Sep 09 at 5:24 pm
The gardenias both lost about a quarter of their leaves in our great freeze of 2010 but otherwise seem fine.
timestocome
21 Jan 10 at 11:10 am