Plants of the Week – July 16

Welcome! Although Eucomis not a real pineapple, its flower stalks with perfectly arranged star-like flowers closely resemble a pineapple.  So, as the pineapple is a sign of welcome, it is fitting that Eucomis lines the front walk to the Arboretum Offices.  Eucomis comosa ‘Sparkling Burgandy’, commonly called the pineapple lily, is a species of African bulb in the Asparagaceae family.  The bulbs will emerge in spring, grow rapidly, bloom in summer and then keep attractive round seedpods until frost.  Besides using it as a symbol of welcome, it makes a unique plant for the garden with its thick glossy foliage and summer-blooming flowers.  They are nice for sunny areas as they prefer full sun yet do not need much watering.  Photo Credit: J. Ahrweiler

Though the common name for Oxalis regnellii is Purple Shamrock, this plant is not related to clover, which is the smaller, similarly foliated plant which is commonly found in lawns.  Oxalis regnellii ‘Purpurea’, is a beautiful ornamental perennial in the Oxalidaceae family with deep purple triangular leaves.  It blooms spring through summer, projecting little pink star-shaped flowers above its foliage which look charming against the purple back drop.  If you cut back the entire plant it will bloom continuously throughout the summer.   Oxalis regnellii is pretty easy to take care of, but there are things you can do to ensure success.  It likes cool air and moist soil while it is growing and prefers bright but indirect light.  Also, if used as an indoor plant it might go dormant in the winter and lose some leaves. But don’t worry! Let it be dormant for around three weeks and then it will refresh itself.  I love this plant in container gardens, its foliage making a nice filler, though it could also be used in the landscape.  Photo Credit: J. Ahrweiler

Oriempet lilies, crosses between Oriental and trumpet and Aurelian hybrids, are a relatively new type of lily.   These lilies were bred to have the beauty of the Oriental lily and the heat tolerance, garden persistence, and range of color of the trumpet lilies.  The oriempet lily Lilium ‘Black Beauty’ is the original clone, bred by Dr. Leslie Woodriff nearly 50 years ago.  It was the first of its kind and is considered a big step in lily breeding.  Now ‘Black Beauty’ graces our gardens with its famous black and red flowers and tightly curled-back petals.  It is extremely hardy, flourishes in every climate and if happy reproduces to create large colonies. Now, they can be seen in bloom in our Scott Entrance Garden and in Cosby Courtyard.  Photo Credit: J. Ahrweiler

Poliothyrsis sinensis is a tree of interest right now as one of the few trees displaying summer interest.  Its canopy is full of bushy yellowish-white flowers providing color whereas other trees are often showiest in spring and fall.  This is a medium-sized tree and useful in the landscape beyond its summer blooms as it is decently dry-tolerant and can withstand adverse conditions.  In fact, it might make a good street tree.  We have one in the entrance garden, displayed against the copper observatory dome, and two more next to the Wister Center.  Photo Credit:  J. Ahrweiler