This plant, which can grow into either a small tree or a shrub, is best known for its lovely white flowers. P. grandiflora is slow-growing and fairly small: generally about eight feet, although some specimens have been known to reach as high as fifteen. Houseplant gardeners will find the tree best to cultivate it from infancy: P. grandiflora makes an excellent container shrub, about three to five feet high, before it fully matures.


Though its dark green, leathery leaves are attractive and it grows in a pleasing shape, the tree’s best feature is its flowers, which bloom in the late spring and summer. These flowers are trumpet-shaped and fragrant – their smell has been compared to chocolate – and their natural white contrasts quite nicely with the darker foliage from which they grow. Though the tree is fairly thin, it will gradually fill out as it matures and some trimming will help it maintain its shape. They can grow in containers or out in the yard and don’t require too much care; this tree can yield wonderful blooms without lots of feeding or effort on your part. P. grandiflora derives its name from the Duchess of Portland; however, it is actually native to both Cuba and Jamaica, where it languished mostly unknown until its rediscovery by Jamaica’s National Arboreum Foundation. Since then, its cultivation has become more widespread across the tropical world, and gardeners in warm places would do well to consider it.

Growing Conditions

• Light: Partial shade or filtered sunlight is best, but the plant should do fine in direct sunlight as well.
• Water: Water it regularly, and make sure to keep its soil moist.
• Temperature: P. grandiflora is cold-sensitive and should never be exposed to frost. For best results, keep it in temperatures higher than 50° Fahrenheit. It should also be protected from cold winds.
• Soil: Unlike most tropical plants, this tree actually grows in alkaline soil rather than acidic. It’s also important to keep it in well-drained soil.
• Fertilizer: Avoid using acidic fertilizers, which will damage it. Application of a balanced, slow-release fertilizer at the end of spring is recommended: remember, P. grandiflora isn’t particularly vigorous and has low energy needs.

Propagation

This tree propagates by stem cuttings: sever some shoots, preferably from a young plant, and remove any leaves or flowers. Then keep them in a warm, humid growing medium like sand or peat until the cuttings root. To increase the chance of rooting, consider applying a root hormone to the new cuttings before you place them in their medium. Once they’ve rooted, transplant to a container and make sure to keep them moist.

Repotting

Generally not necessary, especially because this tree is often cultivated in the ground anyway, but gardeners who choose to grow P. grandiflora in a container may find it beneficial to repot it if the tree is showing signs of stress or is clearly beginning to outgrow its container.

Varieties

There are several other small and similar flowering plants in the Portlandia genus, including P. albiflora and P. harrisii. All Portlandias are native to Jamaica. This genus is closely related to gardenias, which they can superficially resemble due to their white flowers.

Grower’s Tips

Consider trimming the shoots back once a year to help it maintain a pleasing shape; though it grows from a single erect stem, the tree will start to branch out as it ages. The easiest way to kill P. grandiflora is to expose to excessive cold, but if you’re keeping it in an indoor container or a tropical area this shouldn’t be a problem. It will keep its flowers for a large part of the year as long as it’s regularly watered and protected: given care, P. grandiflora is a great and consistent source of fragrance.