Canopy trees grow over 30 feet tall. All trees and green plant leaves use sunlight energy, water and carbon dioxide and produce oxygen for all animal life to breathe. Tree trunks, branches, leaves and roots store carbon, so carbon dioxide, a greenhouse gas, does not rise into Earth’s atmosphere to blanket our planet. Florida has more than 300 native tree species critically important to biodiverse natural habitats. Homeowners are familiar with a few tree species like pines, cedars, elms, hollies, maples, oaks and sycamores. There are many attractive and useful native trees that homeowners can grow to enhance their landscapes.
Sugarberry, Celtis laevigata, makes a fine lawn specimen, summer shade tree and addition to a naturalistic wildlife and butterfly garden. Cold hardy in zones 5a–10b, Sugarberry ranges throughout Florida north to coastal Virginia, west to Central Texas, Oklahoma and Kansas, and north up the Mississippi River basin to the confluences with the Missouri and Ohio Rivers. It grows in full sun to part shade in moist, humus-rich wet to well-drained soil in or near floodplains and river swamps. It matures about 60 feet tall, with a 30 foot spread, and lives up to 150 years. Soil can be sandy, clay or rich and moist. Sugarberry tolerates acidic or alkaline pHs, salty air, urban air pollution and is drought-tolerant once established.
The single gray trunk is straight, usually smooth and may have warty outgrowths and rows of small holes. Woodpeckers, especially sapsuckers, drill the holes which fill with sweet sap that attracts ants, butterflies and other insects. Warty growths on the trunk may grow to heal over the woodpecker holes. The closely related Hackberry, Celtis occidentalis, a smaller species, is not native to Florida. The natural ranges do not overlap in the Southeastern Coastal Plain.
Deciduous Sugarberry leaves are simple, 1 to 6 inches long, wedge-shaped, and taper to a long pointy tip that curves downward. Leaf edges are finely toothed, and light green in color. Leaves alternate along the twigs which have a zig-zag appearance. The tree is quite fast-growing, with large branches that droop with age. Attractive Sugarberry is used in parking lot islands, home landscapes and as an urban shade tree.
Small greenish-yellow flowers are borne in spring as new leaves emerge after winter. Fruit ripens by fall and persists until eaten by birds and other wildlife. A host of beneficial insects, butterflies, ants and flies sip juices from the rotting fruit. Songbirds then prey on the insects.
This beautiful canopy tree is a host plant for four butterfly caterpillars — Hackberry Emperor, Tawny Emperor, Question Mark and American Snout — and the spectacular Io moth caterpillar. Adult female butterfly and moths lay eggs on the host plant leaves and after hatching the caterpillars eat leaves. Caterpillars grow for about 10 to 14 days before finding a hidden safe place where each enters the pupal stage of its life cycle. Adult butterflies emerge in 10 to 14 days and then mate and lay the next generation of eggs.
Asian wooly aphids, Shivaphis celti, entered the U.S. in 1996 where Chinese Hackberry was introduced. This aphid now lives and breeds on the undersides of native Sugarberry and Hackberry leaves. These tiny wooly insects are white to pale bluish and can fly and scatter like mini snowflakes. Some can be hosed away with water. Using insecticides would kill butterflies, caterpillars, bees and other insects and spiders, birds and lizards that eat the smaller prey. While a quick dousing of the aphids on the leaf will kill only them, there are too many and the tree is too tall to treat every leaf. When the tree sheds its leaves in fall, the current year’s aphids will die with the leaves. New aphids hatch when new leaves emerge in spring.
Ladybugs do eat the Asian Wooly Aphids. The Harvester caterpillar, Florida’s only carnivorous butterfly caterpillar, eats native wooly aphids but has not yet developed a taste for the Asian Wooly Aphid. Even heavy aphid infestations do no long-term damage to Sugarberry or Hackberry trees. In late winter, just before leaves emerge, soil-applied systemic insecticide containing imidacloprid is an effective aphid control when there are no caterpillars on the tree.
Allelopathic chemicals in shed Sugarberry leaves inhibit seed germination and growth of many other plants. For more information, visit https://edis.ifas.ufl.edu/st138.
Jane Weber is a professional gardener and consultant. Semi-retired, she grows thousands of native plants. Contact her at email@example.com or phone 352-249-6899.