UNITED STATES—It’s presumptuous to believe that all the fancy breeding that is done to enhance the characteristics of flowers necessarily ‘improves’ them. Breeding only makes flowers more appealing to those who enjoy them in their gardens. Most flowers were already quite efficient for their intended function in their respective natural habitats long before humans started tampering with them. As far as flowers are concerned, they only need to get pollinated.
Some flowers use flashy color or patterns to be visually attractive to pollinators. Others use fragrance to be olfactory appealing. Small but profuse flowers that are neither colorful nor fragrant have given up on insect or animal pollinators, so instead rely on the wind to disperse their pollen.
Not many flowers are both remarkably colorful and remarkably fragrant like freesia, lilac and wisteria were earlier in spring. Lily and bearded iris are of course very colorful, but not all types are fragrant. The big and bold flowers of cereus cactus, moon flower and angel’s trumpet are only fragrant because they bloom at night, and rely on nocturnal pollinators who benefit from a bit more guidance in the dark.
Many fragrant flowers are somewhat showy, like gardenia, star jasmine, pink jasmine and honeysuckle. (However, gardenia are almost never healthy and showy locally.) Many of the most reliably fragrant flowers are really not much to brag about. Pittosporum tobira, Pittosporum undulatum and sweet osmanthus are known more for the appealing evergreen foliage than for their small and nondescript flowers. The flowers of sweet osmanthus may actually be difficult to find amongst the obscuring foliage. Night blooming jasmine is sometimes planted around corners or in the background because even the foliage is not too appealing, although the powerful candy-like fragrance is a favorite for warm evenings.
Fragrant flowers can be annuals like sweet alyssum, bulbs like hyacinth, or perennials like tuberose. Woody plants with fragrant flowers can be vines like stephanotis, shrubs like mock orange (Philadelphus spp.), or trees like Southern magnolia. Some have brief bloom seasons, while others bloom for quite a while.
Highlight: Pittosporum tobira
There are too many other plants known as ‘mock orange’ for Pittosporum tobira to still go by that name, which is why it is more commonly known by its Latin name, or simply as ‘tobira’. The pleasantly fragrant flowers do not smell too much like those of orange anyway. The glossy and dark green leaves are like those of some hollies, without the distinctive prickly points. ‘Variegata’ has lighter green foliage variegated with white, but does not bloom as much. Dwarf cultivars, both variegated and unvariegatd, bloom even less. ‘Variegata’ has a tendency to occasionally produce stems of green (unvariegated) foliage that grow more vigorously and can overwhelm the original variegated growth if not pruned out. Common green Pittosporum tobira can grow as a small tree in the partial shade of larger trees, but is more often maintained as dense shrubbery less than ten feet tall. It makes a nice dense hedge in full sun, but unfortunately does not bloom if shorn regularly. All cultivars are resilient to drought once established.
By Tony Tomeo