Weekly planter: Vietnam gardenia has beautiful solitary flowers

A gardenia is a plant for skilled gardeners who like a challenge. The Gardenia augusta “Vietnam,” which is from Southeast Asia, likes acid conditions. Growing it in alkaline soils means keeping on top of its nutrition, but the beautiful, solitary flowers, with lustrous white petals forming pinwheel-like corollas, should make the effort worthwhile.

The shrub, in the coffee family, has somewhat quilted leaves. Several of the small shrubs planted together make a nice bed. It is a cold hardy plant that blooms almost constantly. It grows to 4 to 6 feet and likes full sun to light shade.

Culture: Gardenias like rich soil and even moisture. Your instructions, therefore, are to amend with organic material such as compost or composted cow manure, apply three or four inches of mulch, and use a fertilizer for acid-loving plants such as ixora and gardenia.

When yellowing in the leaves becomes apparent (more likely in Miami-Dade than in Broward County), use a chelated iron drench. Chelated iron keeps the iron available to be absorbed by plant roots. Gardenias also are susceptible to nematodes. Mulch and a good nutritional program can help the plant grow anyway; grafting on G. thunbergia rootstock, which is resistant to nematodes, is best.

MIAMI HERALD ARCHIVES

This story was originally published January 7, 2016 at 8:40 PM with the headline "Weekly planter: Vietnam gardenia has beautiful solitary flowers."