Plant of the Month

Gardenia (Gardenia jasminoides)

Gardenia is one of the first plants that new Floridians want to put in their gardens because they remember these fragrant white flowers as corsages and as table decorations. But gardenias are fussy, and many people are disappointed. For best results, plant them in an open flower bed away from house foundations, pools and walkways. They are acid-loving plants, and the high alkalinity near concrete almost guarantees they will have nutritional problems.

Most gardenias are big growers and should not be planted close to doorways or in other tight areas. I planted my gardenia from a 3-gallon pot in 1982, and it is now 10 feet tall and 12 feet across. Gardeners who plant them in the wrong places find they have to prune them back. Since they bloom at the ends of the branches, pruning eliminates flowers.

In Florida, gardenias must be grafted if they are planted in the ground because microscopic nematodes can clog up the root system and kill them. They are grafted onto Gardenia thumbergia, a nematode-resistant stock.

Look for the main show of flowers from mid-April to mid-May. A scattering of flowers will continue through August if the plants are well fertilized. Fertilize in March, June and October with an ixora/gardenia fertilizer to combat nutritional problems. Try the small growing `Vetchii' gardenia, which grows to about 4-5 feet and blooms off and on throughout the year. The flowers are much smaller that those on the larger plant, but the fragrance is the same. Big growing varieties include: Miami Supreme, Glazerii, August Beauty and Mystery.

• Origin — China
• Foliage — oval pointed leaves
• Nutritional requirements — Acid fertilizer three times a year
• Soil requirements — Prefers acid soil but can tolerate some alkalinity if fertilized regularly
• Salt tolerance — None
• Drought tolerance — Low
• Light requirements — High to medium
• Growth rate — Moderate
• Propagation — Graftings
• Major problems — Nematodes, chlorotic foliage, sucking insects (such as scale, mealybug and whitefly), thrips (cause flower drop), sooty mold (causes blackened leaves)
• Environmental problems — None
• Availability — Just about any good nursery and many garden centers
  

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