Common: common gardenia
Pronounciation: Gar-DEE-ni-a jas-min-OYE-deez
Sunset 7-9, 12-16, 18-24
Landscape Use: Mesic and oasis landscape design themes, foliar and fragrant accent. landscape borders, entryways, container plant.
Form & Character: Mounding, rounded and formal, oriental, clean, vulnerable.
Growth Habit: Evergreen, woody perennial shrub, slow growing and very short lived in Phoenix. Mostly it seems like one is 'growing' chlorosis when attempting to cultivate gardenia in Phoenix landscapes. Because of this the actual mature height of gardenia is almost never realized in Phoenix.
Foliage/Texture: Glabrous, dark green leaves, simple and entire, prominent venation, nearly sessile; medium coarse texture.
Flowers & Fruits: Flowers are large (up to 4 inches across) and fragrant, borne singularly and at terminal meristems; fruits are inconspicuous green.
Seasonal color: Large white fragrant flowers in spring and fall.
Temperature: Gardenia struggles mightly during the high heat of summer in the lower desert when temperatures exceed 110oF; it is however tolerant of the somewhat cool to cold Phoenix winters.
Light: Partial sun/shade, NO western sun.
Soil: Gardenias are quite intolerant of alkaline and saline soils = foliar intervenal chlorosis and general weak and poor vigor. All plantings must be thoroughly prepared by amending heavily the soil with acidic peat moss and mulching the soil surface heavily with composted forest mulch. The ideal soil is acidic (pH at 4-5.5), highly organic and well drained. Because of salt sensitiveness, fertilize with controlled release azalea or camellia fertilizers.
Watering: Regular, keep soil evenly moist.
Pruning: Very little needed
Propagation: Softwood cutting, seed (will germinate readily at 75oF).
Disease and Pests: Aphids, thrips, white flies, scale, root rot (poor draining soils), flower bud drop (caused by sudden changes in watering or temperature conditions)
Additional comments: This is a very difficult, extremely high maintenance shrub to grow in the lower desert because of environmental incompatibilities such as alkaline soil, but for some gardenia fanactics the rewards of the wonderful flower fragrance make it worth while to try....and try again. There are many named cultivars.