Gardenias have one of the most recognizable flower scents. Their highly fragrant, 2- to 3-inch, double white flowers are popular worldwide. In the United States, gardenias, Gardenia jasminoides, are commonly grown in southern or coastal climates. In central to northern regions, they can be grown outdoors from April through October, but must be overwintered indoors.
GARDENIAS THRIVE IN MOIST, RICH, AND ACIDIC SOILS that are well-drained, whether grown in the ground or a container. They prefer full to part sun, but should be protected from extreme heat. Indoors, place them in a bright window in a room that is kept cooler during the winter.
THE MOST COMMON COMPLAINT ABOUT GARDENIAS is bud drop before the flowers open. This can be caused by excessive heat, dramatic changes in air temperature, or extreme fluctuations in soil moisture.
MOST GARDENIAS ARE HARDY TO USDA ZONE 8, which means they can survive a low temperature of 10 to 15 degrees, although they may not escape damage. USDA zones in Kentucky range from 6a to 7b, so if you are in zone 7 and want to push your hardiness zone boundaries, try gardenia ‘Kleim’s Hardy.’ It is hardy to zero degrees; another variety, ‘Chuck Hayes,’ is hardy to 10 degrees.
WE USUALLY GROW GARDENIAS AS HOUSEPLANTS IN THE WINTER in our area and as patio plants in the summer. Because they are so cold-tolerant, they can be one of the last plants you bring indoors for the winter and the first plants you take out in the spring. When they are outside, fertilize them regularly to encourage flower production and keep the glossy, dark green leaves looking their best.
ASK THE GARDENER
by Angie McManus
Q: I have gnats in my houseplants; what do I do to get rid of them?
A Fungus gnats are more of a nuisance than anything. They will not harm humans or animals, but the larval stage of these gnats lives in the soil of our plants and can damage the roots, so control is necessary to prevent plant stress.
Good sanitation and drainage will help keep the numbers down. They like to lay their eggs in damp soil, so make sure the plants are not being overwatered and there is no standing water in the saucer.
Sticky flytraps are a great way to eliminate these pests. You should be able to find these at your local garden center. They are bright yellow and sticky and you can either lay them in the soil or just place them around the house and the gnats will find them. The flying adults are attracted to the color, and once they come into contact with the trap they will not be able to free themselves. This will prevent them from reproducing and stop the cycle. There may be many generations in one year, but their life cycle is approximately one month long. Check and replace the traps once they are covered in these insects.