THE COASTAL GARDENER:Plumeria fanciers keep it coastal

Last summer, while on the island of Oahu, I abandoned my wife and girls for most of the day and went on a plant quest. This happens a lot. The Sawdust Festival, an Angel’s game, Disneyland; they all sound like horticultural trips to me. I’m not sure why my family doesn’t always see the full potential in such family outings.

Anyway, one of the world’s great plumeria gardens is on Oahu. About a 40-minute bus ride from Waikiki is the Koko Crater Botanical Garden. The plumeria plantings at the garden are extensive, well labeled and come in a huge variety of colors, forms and plant sizes.

As little as 20 years ago, plumeria in Orange County were primarily the domain of serious plant enthusiasts only. Today, plumeria are a common sight in gardens throughout the county.

However, as many of you may know, plumeria grown within a few miles of the ocean may be lush and leafy but bloom poorly. I have watched many large plumeria in coastal gardens for years. Many of these, although healthy, never seem to have many flowers.

Plumeria need heat. A long, hot summer, like that of the Koko Crater Botanical Garden, triggers a plumeria to bloom. The mild, cool temperatures along the coast grow terrific plumeria, but often don’t provide a long enough or hot enough summer for the plants to bloom well. A plumeria in Anaheim may bloom heavily, while the same plant growing in a Costa Mesa garden may be leafy and pretty, but flowerless.

Curtis Hayes and George Crouchet, respectively president and past president of our local South Coast Plumeria Society, have a few suggestions for coastal plumeria fanciers. First, start with a named variety that is proven to bloom well in a cool coastal garden. Avoid any plumeria that simply is labeled as “Pink” or “Yellow.” You will not know the real names of these plants. In your garden, you wouldn’t add an apple labeled “Red” or a rose labeled “Pink”; don’t choose a plumeria with this labeling either.

The most foolproof plumeria along the coast may be the beautiful Celadine. It is especially easy to grow and bloom in our climate. Because of its long-lasting flowers, it is the most popular plumeria in the world and is popular for making leis. In a garden, I believe its large yellow flowers with pale margins are especially showy, more so than most pinks or reds, and it is one of the most fragrant selections available. Red-flowered plumeria need the most heat of any color and are a poor choice for a coastal garden.

Since plumeria need heat and a long summer to bloom well, it is best to locate your plants in the warmest area of your garden. Even temperamental varieties in a coastal garden might be coaxed into bloom when grown in full sun against a south or west-facing wall that reflects light and heat.

Grow plumeria in pots or in the ground. In the ground, choose an area that has good drainage and does not get frequent, shallow water, especially in the winter months when plumeria prefer little water. Sandy soil is best, but a raised bed with a loose, gritty soil and good drainage will do. In containers, also use a loose, fast-draining soil. Cactus mixes usually work quite well. I grow my potted plants in a quality organic potting soil to which I have blended about 30% to 40% pumice for drainage.

Curtis and George of the Plumeria Society suggest feeding plumeria with a balanced fertilizer in late spring, just as the new foliage begins to expand. A month or two later, switch to a fertilizer higher in phosphorus to induce more and larger flowers, and better color. Keep feeding regularly, especially potted plants, until early October. There is no need to fertilize in the fall or winter months.

When your plumeria are leafy and growing, from spring through fall, water regularly. The frequency of irrigations will depend upon the size of the plants, whether they are potted or in the ground, the soil and the weather. Currently I am watering my biggest eight-foot potted plants about twice a week while my smaller plants get a drink daily. I always water thoroughly.

In the late fall, as the plants begin dropping their leaves and slipping toward dormancy, reduce irrigations significantly. During the winter, weather conditions will dictate whether you should water, but a dormant, leafless plant will not need little water. Plants in the ground will get most of the water they need from winter rainfall. A plumeria planted in a mixed landscape with automatic sprinklers turned on during the winter is likely to rot.

To learn more about growing plumeria in southern California and an opportunity to share information with others that have a similar interest, attend the South Coast Plumeria Society’s August 6 open meeting at 1 p.m. at the Murdy Park Community Center, Norma and Goldenwest Street in Huntington Beach. For more information, visit their website at ww.home.earthlink. net/{tilde}gcrouchet.