Garden Help: Plumeria go from ugly duckling to swan plant

If you have plumeria in your landscape, you are enjoying the transformation of the ugly duckling plant to the lovely swan. My husband asked a few months ago why I was keeping “that ugly stick plant” as I lugged it to a protected area, tucking it away from the cold. Over the last few weeks, he again noticed the plant and now understands why I made the effort.

Plumeria are ornamental plants native to Mexico, Central America and Venezuela. In their native habitat, they grow on hillsides in porous soils along the coast. Soils are typically poor and plants are exposed to full sun in very hot, dry environments.

The plant was named for Charles Plumier, a French monk and botanical explorer who made several trips to the Caribbean in the late 1600s. The genus Plumeria is in the Apocynaceae family, so it’s related to oleander, confederate jasmine, allamanda, periwinkle, mandevilla and desert rose. Like most members of this family, they have milky sap that can cause dermatitis. If skin is exposed to the sap, wash promptly with soapy water.

If you’ve ever visited Hawaii, you may have noticed the garden leis often sold for their beautiful colors and fragrance. These leis are made from the flowers of plumeria, which aren’t native to Hawaii, but the plants are certainly tied to the islands. The flowers have five waxy, twisted petals that hold up amazingly well in leis and can also be used as a cut flower. Flowers naturally occur in white, yellow and red but thanks to hybrids, the color palette now includes multiple shades of orange and pink. Flowering occurs from spring through fall, so it has an extended flowering season compared to many ornamental plants. The wood is popular in making drums, bowls, cabinets and furniture.

Plumeria are fast growers if conditions are good, and develop a vase to rounded shape. They are salt-tolerant, so for beach dwellers plumeria is a great option for a specimen plant. Plants have thick rubbery stems and are deciduous, so they lose their leaves in winter. Once warm weather returns, plants leaf out at the stem tips. Leaves are 12-18 inches long and have prominent midrib veins that add texture to the landscape. Flowers are also borne in dense terminal clusters at stem tips.

Also called frangipani, Plumeria spp. are tropical plants listed for zones 10 and 11 and are grown as small trees in south Florida. However, I don’t recommend that you plant yours in the ground unless you’re simply sinking the container to keep it from blowing over. They aren’t cold hardy, so it’s better to grow them in a container and move them into a protected area during cold weather.

Plumeria grow in average sandy loam soil that’s either slightly acidic or alkaline. Because we’re growing plumeria in containers, make sure the media contains organic matter but is well-drained.

They enjoy moisture during the warmer months, but the media should dry out before adding water again. When plants are dormant, water sparingly. If the media/soil is too moist, plants will suffer from stem and/or root rot. If the container media becomes compacted, it’s time to repot.

Place your plumeria in an area that gets plenty of sun — the more the better for flower production. Fertilize with a bloom-inducing fertilizer once the warm weather arrives to encourage continuous blooms. Make sure the first number on the fertilizer label (nitrogen) is low compared to the next two (phosphorous and potassium) or you will be rewarded with lots of leaves and few flowers. Follow label directions based on the analysis and taper off fertilizer applications in October so plants naturally go dormant.

The list of potential problems is short outside of root/stem rot. Inspect plants for scale insects, mites and hibiscus bud midge. Rust is sometimes a problem later in the year but it doesn’t warrant sprays, because leaves will soon drop as plants approach dormancy. Simply discard the affected leaves as they fall so new leaves are not affected the following spring.

Over time, plants will likely outgrow their containers or may get too tall for the desired space. The good news is that they are relatively easy to propagate and this is a great way to control their size. Plants can be propagated by stem cuttings, seed, grafting and air layering. Seed is often used when creating new hybrids but it is a slow process because it takes three or more years for the plant to flower. Stem cuttings is the easiest and most-used method because it provides almost instant floral gratification.

To start new plants by stem cuttings, take cuttings in spring to early summer. Cuttings should be 12 to 15 inches long; avoid those that are flowering. The base of the cutting must be from mature wood that is gray and firm, plus the cutting includes the terminal growth (stem tip). Place the cutting in a shaded location for three to five days to allow the cut surface to heal (callus). You can remove the leaves or cut leaves in half to reduce the leaf size, which helps reduce water loss through the leaves (transpiration).

After the cut surface develops a callus, put the cut end into a pre-moistened media about three inches deep. Don’t water the plant for the next five to six weeks, and you may need to protect it from rainfall. During this time the plant will develop new roots. When new leaves emerge, lightly water the plants but make sure the media doesn’t stay too moist.

Check local nurseries or online for these unique plants that will add a touch of the tropics to your landscape. For more information on propagating plumerias, go to edis.ifas.ufl.edu/pdffiles/EP/EP48900.pdf.disclosure.

Terry Brite DelValle is a horticulture extension agent with the Duval County Extension Service and the University of Florida/IFAS.