PICAYUNE — Now is the time of year when spring blooms are a distant memory but we still aren’t firmly settled into the sultry summer days that Mississippi’s coastal residents know all too well. Many our native shrubs and smaller trees are really using this time to shine. Their leaves are exhibiting a robust and lush appearance, having recently grown by leaps and bounds following the spring rains.

As I drive down our half-mile service road each morning, I have a chance to drink in a last wee bit of green before sequestering myself in the office. The olive tones of wax myrtle (Morella cerifera) flaunt their fluffy evergreen branches in the roadside mix. This shrub is also known as southern bayberry, and I never tire of talking about its aromatic leaves, or it historic and landscape uses such as candle making and repelling insects such as fleas and cockroaches.

Wax myrtle has an extremely tough, drought tolerant nature, and the ability to grow in a wide range of site conditions. It makes a great choice for your wildlife garden or home landscape. Recently, I learned a surprising new fact: wax myrtles are “nitrogen-fixing” plants. Although this is a well-known characteristic of plants in the legume family, it was an amazing trait to discover about this common native. Wax myrtles are often described as being excellent “pioneer” plants, and now it is clear why since their roots are associated with nitrogen-fixing bacteria that provide a vital nutrient needed for plant growth. Have you ever heard of farmers who till in a crop of winter clover? They do this to raise the nitrogen levels in their soil to feed later crops, making good use of clover’s nitrogen-fixing ability.

So, what can you learn from this? If you have challenging site conditions, such as a new home with imported, compacted soil, wax myrtle is a great choice, having a pretty good guarantee for top performance. Although it is a short-lived shrub, perhaps lasting for only 15 to 20 years, you can choose other trees and shrubs to grow in association with them, taking their place after this fast-growing plant has reached maturity.

Two other outstanding shrubs that are looking quite handsome right now in our exhibits are titi (Cyrilla racemiflora) and red bay (Persea borbonia). Beekeepers may not know titi by name, but they may be very familiar with this large shrub which is seen on wetland soils because of its long sprays of white flowers that are bee magnets. The flower nectar is also attractive to butterflies – and even bears!

Titi grows in acidic, wet soils throughout the southeastern United States. It suckers from the roots, and will develop into large thickets that will provide excellent protection for birds, deer and other mammals. Its leaves are a valuable deer browse and the seeds are eaten by many animals. The shrub grows more densely and flowers more prolifically in the full sun but it will also grow in shade, where it attains a looser structure.

You will do best with titi if you give it room to grow. Don’t try to contain it or you will destroy its natural beauty. It likes to sprawl, and will grow quite large, to 15 feet or more. The form is reminiscent of rhododendron shrubs in the Smoky Mountains.

Titi, also known as leatherwood, is found throughout the Crosby Arboretum, such as along our service road. Several large titi clusters are found in the center island of the loop drive behind our Visitor Center, and in the uppermost tip of the North Savanna. Here, a large colony can be seen growing along the western edge of the woodland adjacent to the pathway.

Titi is often mentioned in magazine articles on southern natives, making it one of the well-known native plants for the South. It is frequently requested at our quarterly plant sales. If you grow this plant, you will see why. In addition to the unusual flowers, the leaves turn beautiful shades of red in the fall.

Several attractive small specimens of red bay can be spotted along our service road and the center island loop. The deep evergreen of this small tree’s leaves really make it stand out in the woodland. Found in our moist coastal hammocks and low woods as well as on drier sites, one identifying characteristic of red bay is that its leaves will often exhibit damage from insect galls. The scent of the crushed leaves is simply heavenly, as this plant is related to the bay laurel (Laurus nobilis) that just might be sitting on your spice rack. The tree also produces an attractive blue-black fruit that provides valuable food and cover for many wildlife species.

At the Arboretum, we have been watching our red bay trees for signs of laurel wilt disease, spread by the Asian red bay ambrosia beetle that entered the United States through Savanna, Georgia in 2002. In 2009, the beetle was confirmed in Jackson County, Mississippi. Female ambrosia beetles drill into the tree’s sapwood to lay its eggs and inoculates the tunnels with the fungus. As the fungus grows, it plugs up the system that conducts water. Unfortunately, all it takes is one beetle to cause the death of a tree.

Laurel wilt unfortunately affects other species in the Laurel family, including sassafras and avocado. If you have red bay or sassafras on your property, you may wish to learn more about this disease and monitor your trees for signs of infection.

For more information, please call the Arboretum office at 601-799-2311, or see our program schedule on our website at www.crosbyarboretum.msstate.edu. Social media links can be found on our homepage. We are open Wednesday through Sunday from 9 a.m. to 5 p.m. and located in Picayune, off I-59 Exit 4, at 370 Ridge Road (south of Walmart and adjacent to I-59).

For further exploration:

Do an Internet search to learn more about the red bay ambrosia beetle.