Gardenias

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Gardenias

Family:  Rubiaceae

(In this I am going to liberally share sound advice kindly provided to me by Paul Crist – a successful grower of these beauties who lives in the Puerto Vallarta area.  In all candor, regarding these magnificent flowers, he is more experienced and conversant on them then am I.  Accordingly, I tip my Ola Brisa Gardens hat to him in grateful appreciation for his input!)

Gardenias are a genus of flowering plants comprised of about 142 species.  These evergreen shrubs are indigenous to the tropical and subtropical areas of Africa, Asia and Australia.  In that natural habitat, they can grow from two to twenty feet or more in height.

Their leaves are glossy, dark green and, depending on the species, can grow from about one to ten inches (2 ½ to 25 ½ cm) long.  Their flowers – many of which have an intoxicatingly sweet scent – are white or yellow and develop either a single or a cluster of blossoms.

But, around here anyway, they are not the easiest of flowers to keep happy!  Given their “druthers”, gardenias prefer moist, well-drained, acidic soil that is rich in organic matter.  If it’s not acidic enough the leaves will turn yellow.

And water?  I like the way Paul said it, “(I use) insane amounts of water during the dry, winter season”.  He finds “it useful to (employ) an oscillating sprinkler underneath the plants (with) the underside spray helping to keep down the spider mites that attack gardenias during the dry season.”

He continues saying that “Watering deeply . . . helps establish deep roots and grows a more hardy plant.  Moistening the surface of the soil without a good drenching can result in a plant (having) more surface roots, which are more susceptible to drying out (this should never be allowed for gardenias).”  And, he is absolutely correct when he says that ”Gardenias like the cooler, moister soil that is at least six to eight inches underground in a well-tended planting bed.”


In his care for gardenias he “regularly use(s) a mild preventive insecticide containing pyrethrins, which is an extract of chrysanthemums. (It) is a fast-acting poison which disrupts the nervous system and causes paralysis of the insects, while at the same time being non-toxic to warm-blooded animals.  (It is) also biodegradable and breaks down quickly in sunlight, moisture and oxygen.”  He adds that, “When using insecticide, (strive) to cover all surfaces, including the undersides, of the leaves and stems.” 

He then says that “Leaf cutter ants adore gardenias, and can strip a plant bare of leaves in one night.”  To thwart them he uses “Trompa” which are pellets that ants find to be delicious.  They take these pellets back to their nests, for a “last supper, as it were.” (I concur that this is the best local product for these little nasties!) 

He suggests that “If you see damage from leaf cutter ants, go out at night, around eleven PM, with a flashlight in hand, and look for the column of marching ants. Follow them back to the nest, and sprinkle Trompa liberally around the nest. One or two treatments usually will “do the job”.

He says that he also” use(s) lots of Miracle-Gro (By) drench(ing) the plants and soil every two weeks” and he advises that the “nutrients are absorbed through leaf pores as well as through roots.”   Obviously well knowing “his stuff” he continues that “Miracle grow has a good mix of trace minerals such as magnesium, which helps distribute phosphorus throughout the plant, so it is, in my opinion, the best water soluble fertilizer for gardenias.”

To this he adds, “I also add a bit of granular fertilizer around the base of the plants about once each month. You don’t need to use much, as it’s a supplement to the Miracle-Gro that provides a more continuous feeding. Use a granular with high phosphorus (rose fertilizers work well).  In selecting fertilizers, the middle number is phosphorous (e.g. 5-10-5).”  He correctly suggests that one “Go for a big middle number.”

In closing he said that to obtain the very best results, the “Gardenias need full sun  . . . all day long. They’ll survive some shade, but won’t bloom.  And be sure to pluck or clip dried blooms, which helps to encourage more flowering.  Gardenias are a challenge in western Mexico, where the dry winter season means more care for a spectacular plant. But the scent and beauty of these regal plants is well worth the effort.”

Gardenia (3 of 4)

Photograph by Paul Crist

Gardenia (4 of 4)

Photograph by Paul Crist

Gardenia (2 of 4)

Photograph by Paul Crist