Southern Catalpa (Bignonioides)

The Southern Catalpa (Bignonioides) is generally described as a perennial tree. This is native to the U.S. (United States) has its most active growth period in the spring . The Southern Catalpa (Bignonioides) has green foliage and inconspicuous white flowers, with a moderate amount of conspicuous green fruits or seeds. The greatest bloom is usually observed in the mid spring, with fruit and seed production starting in the summer and continuing until summer. Leaves are not retained year to year. The Southern Catalpa (Bignonioides) has a long life span relative to most other plant species and a rapid growth rate. At maturity, the typical Southern Catalpa (Bignonioides) will reach up to 66 feet high, with a maximum height at 20 years of 66 feet.

The Southern Catalpa (Bignonioides) is easily found in nurseries, garden stores and other plant dealers and distributors. It can be propagated by bare root, container, seed. It has a slow ability to spread through seed production and the seedlings have medium vigor. Note that cold stratification is not required for seed germination and the plant cannot survive exposure to temperatures below -18°F. has medium tolerance to drought and restricted water conditions.

Uses of : Landscaping, Medicinal, Culinary, etc.

Southern catalpa is primarily used today as a large ornamental shade tree. It is widely planted in urban areas as a street and lawn tree. Conservation uses include being planted in windbreaks. Some plant it to attract the catalpa worm, which are harvested and used as fish bait.

General Characteristics

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Required Growing Conditions

Trumpet-creeper Family (Bignoniaceae). It is a perennial deciduous tree which readily grows in USDA Hardiness Zones 5 to 9. This is a U.S. native. At maturity, the height can vary from about 25 to 40 feet. Catalpas prefer moist, deep, well drained soil, but adapts to dry or wet soils. The soil pH may range from 5.5 to 7.0. It prefers an open sunny space to partial shade. The crown is often forked. Its longevity is about 40 to 50 years.

The tree bark is separated into irregular shallow fissures with reddish-brown scales. On young tree seedlings the bark is thin and easily damaged by impact, or rodents.

Twigs in winter have a unique identifying characteristic. They have sunken leaf scars which resemble suction cups. Their whorled arrangement of 3 “moon crater” scars per node is another trait easily identified. They are grayish-brown in color.

Leaves are simple, may be opposite or whorled (3 per node), pinnately veined, 5 to 12 inches long , 4 to 6 inches broad, heart shaped at the base, and have a long petiole with entire margins and soft pubescence on the underside, which is also a lighter green than the top surface.

The flowers of catalpa are perfect. Flowering takes place from May through July. They occur in bell-shaped corollas of 5 lobes. Individual flowers are showy, with the 5 petals in each flower being unequal in size, white with purple spots and orange stripes at the throat, in branched, upright clusters. The petals are up to 1.5 inches long.

Seedpods are slender and green in the summer growing from 6 to 24 inches long, and ½ inch wide looking ‘cigarlike’. They mature in the autumn, turn brown, split open lengthwise to let seeds fall in the spring. The seedpod generally stays attached to the tree limb over winter.It was first cultivated in 1726. It was originally found in the Gulf Coast states of Florida, Georgia, Alabama, Mississippi and Louisiana. It has since spread to many states east of the Rocky Mountains.

Cultivation and Care

When placed as an ornamental in a yard setting care must be taken to ensure it is not too close to a building, fence, property line or septic system. Ample space should be provided to let it reach a mature height.

General Upkeep and Control

The biggest management problems with a catalpa tree used as an ornamental are litter and smell. It will drop a heavy load of flowers in the spring, then a plentiful supply of leaves in the fall, and finally a lot of large seedpods in the winter. Green leaves give off a disagreeable odor when crushed.

Pests and Potential Problems Larva of the catalpa sphinx caterpillar (Ceratomia catalpae) eats leaves. Almost complete defoliation may occur in some years.

Verticillum wilt will make the branches die, and can eventually kill trees. Powdery mildew causes a white powdery coating on the leaves. When severe the leaves turn yellow and drop.

Environmental Concerns It is an invasive, weedy tree which escapes cultivation easily. The flowers, long seedpods and seeds fall down from spring through winter, and create a mess on the ground anywhere near the tree.

Cultivars, Improved, and Selected Materials (and area of origin) There are two species of catalpa native to North America, northern catalpa (Catalpa speciosa) and southern catalpa (Catalpa bignonioides). They appear very similar but are two distinct species. Two varieties of C. bignonioides have been documented: ‘Aurea’ and a dwarf variety named ‘Nana’.

Control Please contact your local agricultural extension specialist or county weed specialist to learn what works best in your area and how to use it safely. Always read label and safety instructions for each control method. Trade names and control measures appear in this document only to provide specific information. USDA, NRCS does not guarantee or warranty the products and control methods named, and other products may be equally effective.

Plant Basics
Category
Growth Rate Rapid
General Type Tree
Growth Period Spring
Growth Duration Perennial
Lifespan Long
Plant Nativity Native to U.S.
Commercial Availability Routinely Available
Physical Characteristics
Bloom Period Mid Spring
Displays Fall Colors No
Shape/Growth Form Single Crown
Drought Tolerance Medium
Shade Tolerance Intermediate
Height When Mature 66
Vegetative Spread None
Flower Color White
Flower Conspicuousness Yes
Fruit/Seed Abundance Medium
Fruit/Seed Seasonality Summer Summer
Seed Spread Rate Slow
Gardening Characteristics
Propagations (Ways to Grow) Bare Root, Container, Seed
Moisture Requirements Low
Cold Stratification Required No
Minimum Temperature -18
Soil Depth for Roots 36
Toxic to Nearby Plants No
Toxic to Livestock No
After-Harvest Resprout Ability Yes
Responds to Coppicing No
Growth Requirements
pH Range 5.5–7.5 pH
Precipitation Range 30–30 inches/yr
Planting Density 170–700 indiv./acre
Soil Textures Coarse, Medium
Soil Depth for Roots 36
Minimum Frost-Free Days 140 day(s)
Salinity Tolerance None
CaCO3 Tolerance Medium
Sustainability & Use
Leaf Retention No
Palatability Medium
Fire Resistant No
Causes Livestock Bloating None

Source: USDA, NRCS, PLANTS Database, plants.usda.gov.
National Plant Data Center, Baton Rouge, LA 70874-4490 USA