Crown Jewel® Gardenia PP19896 is a low-growing, spreading to prostrate Gardenia with intensely fragrant, white, medium-sized flowers in early summer. Bright green foliage is medium to small sized for the species. While cold-climate gardeners must grow their gardenias in pots, in USDA Zone 7 and warmer gardenias are grown outdoors, permeating the garden with fragrance.
Providing an acidic loam is crucial for plant health and successful blooming in some plants. Gardenias, along with blueberries, fragrant native azaleas and beautiful evergreen camellias, all prefer moist, loamy, acid-rich soils with the pH ranging between 5 and 6. Amending the soil with organic soil conditioners facilitates the development of the right blend. Compost made from pine needles, oak leaves or Douglas fir sawdust, followed after planting with a mulch of pine straw, goes a long way toward this goal. Soybean meal, cottonseed meal or alfalfa as a green manure also create more acid conditions.
Another organic tip is to add powdered sulfur to the soil a few months before planting according to package directions to lower the pH, making the soil more acidic (also a good tip for Iris ensata, Japanese Iris).
Iron Chelate is an organic form of iron, and provides micronutrients in a form available for absorption by plants. Spraying the foliage with iron chelate typically eliminates yellow, mottled choloritc leaves deficient in iron by supplying iron and facilitating the uptake of nitrogen.
These wonderful woody plants are best provided with full to partial sun (a bit of afternoon shade is great) and good air circulation in a cooler, woodsy environment. Don’t plant near the reflective heat of concrete or asphalt. Protection from cold winter winds helps to prevent tip dieback at the colder regions of the plants’ range. Light applications of commercial azalea fertilizer or diluted acid-forming fertilizers are ok, but too much can burn tender roots.
In particular, Crown Jewel® Gardenia was selected from a controlled cross between the dwarf ‘Kleim’s Hardy’ and the cold-hardy, twice-blooming ‘Chuck Hayes’ by Philip Dark of Oakmont Nursery in Chathem County, North Carolina. Heavy June blooming repeats until frost. Highly perfumed Crown Jewel® Gardenia grows about 6 inches /year with the potential to reach 2 feet in height and a spread of 4 to 6 feet wide, ideal for garden beds. Dark is a member of the consortium of growers and breeders that make up Garden Debut®.