If you’re looking for a tree that’s not only an attention-grabber but also attracts pollinators with its fragrant blooms, then the catalpa fits the bill. This tree adapts to a wide range of soils and climate conditions and creates a beautiful, bright-green canopy of heart-shaped leaves and orchid-like flowers from spring until the early summer.
The catalpa is fairly tough, so you won’t need to fuss over it to keep it healthy and growing strong.
Order catalpas online or purchase them from a nursery. Until they’re older, young catalpas have thin bark that is easily damaged. Avoid saplings with scars on the trunk, as this can lead to fungus or water damage.
Wrap your sapling before transporting to protect it. If you have your heart set on planting a catalpa but can’t find one locally, or you have no way of transporting one, you’ll find seeds online.
A soil pH of between 5.5 and 6 is ideal, but the catalpa grows well in a wide range of soil conditions as long as it has good drainage. Plant it in fall or spring in a hole that’s twice as deep and wide as its root ball. Seeds can be planted into the ground in the spring, or grow them in a pot that provides good drainage. Fill the pot with potting soil, sprinkle a few seeds across the surface, and lightly cover them with one inch or less of additional potting soil. Set the pot in a shaded area and transplant the new seedlings in the spring.
Finding the perfect spot to grow your catalpa isn’t hard. Catalpas will thrive in full sun or partial shade. However, the more sun it has, the happier your tree will be. Find a spot in the yard or garden where it will get at least four to six hours of direct, unfiltered sunlight every day.
If you live in a region that doesn’t have a ton of rainfall, the catalpa can handle it. Until a sapling is established, water it well: at least once per week. After it’s rooted, you’ll only need to water the catalpa during periods of short drought. Heavy rains and short-term flooding don’t usually affect these trees, either.
Moist, rich soil that drains well is all this tree requires — unless the soil is particularly sandy, or a clay or silty type. If so, add an all-around fertilizer like 10-10-10 each spring to provide the tree with balanced amounts of phosphorus, nitrogen, and potassium, which encourage leaf growth and root development. Fertilizing also strengthens the tree so it can better fend off disease.
Most catalpas grow best in hardiness zones 5 through 9 — most of the U.S. — depending on the type.
Native southern catalpa varieties grow in Florida, Louisiana, and other southeastern states, but are also popular in residential areas. The Chinese catalpa, which is the most tolerant type, is hardy to zone 4, meaning it can handle the lower average winter temperatures found in the northernmost parts of the U.S. mainland.
Remove any suckers that appear on the ground around or on the tree’s trunk. Pruning in the late fall or early spring after the blooming has ended encourages healthy growth. If you start pruning the tree when it’s young, it will have more stability and a more attractive form as it ages.
Make a habit of pruning off low-growing branches to allow for easy maintenance around the tree.
Catalpas are deciduous trees. They shed their leaves and long seed pods in the fall or after the first frost. Cleanup can be an extensive project, but otherwise, these trees require no special care for winter.
However, fall pruning can help prevent limb breakage or damage if there’s snow or ice buildup during cold weather events.
Each seedpod that drops is a potential new tree, so it’s not hard to gather seeds. In addition, the seedpods will take root if left on the ground after they’ve fallen from the tree.
Most catalpa types begin producing the pods five to seven years after planting. Propagation from root or branch cuttings is also an option for starting new catalpa trees.
Purplish or bluish-brown streaks under the newly formed outer wood of catalpas are usually symptoms of verticillium wilt. Unfortunately, there are no effective remedies for this disease. It invades the root system and cuts off the tree’s water supply. The leaves often turn yellow, then brown, before falling off. Applying a fungicide at the roots may help.
If you see a white powdery substance on the leaves, it’s likely powdery mildew. A simple DIY fungicide will usually clear up this common problem.
The main pest for a catalpa tree is the black and greenish-yellow catalpa sphinx caterpillar. An infestation can completely strip off the tree’s foliage within one summer. However, if the tree is healthy, it will recover the following year, so don’t be too alarmed.
Natural predators help control caterpillar numbers. Catalpa caterpillars are a popular bait used to catch perch, catfish, largemouth bass, and other fish species. Some people even grow catalpa trees just to lure these caterpillars in.
The catalpa is an ornamental tree and once it's matured, makes a lovely shade tree. Its size, lush green color, heart-shaped leaves, bell-shaped blooms, and cigar-shaped seedpods are hard to ignore.
Bees, butterflies, and especially hummingbirds are fond of the aromatic catalpa flowers, so the trees are perfect for a pollinator garden. Catalpas also attract birds and wildlife that find shelter within their lush foliage.
The catalpa is similar in appearance to another tree, the Paulownia, which was introduced in the U.S. in the mid-1800s from Europe and Asia. In some areas, though, it’s considered an invasive species due to its prolific growth, so do some research before planting this alternative.
Like the catalpa, the Western redbud tree produces both seedpods and blooms. Its seedpods can be brown, green, or purple, and its blooms are vivid purplish pink.
Herbal medicine practitioners often use catalpas in a tea or poultice form to treat skin wounds, abrasions, a mild sedative, or a laxative. While the bark, leaves, and fruit are safe to use, the catalpa roots are highly poisonous.
Only the flowers and seedpods from one type of catalpa, the Chinese catalpa, have been a documented food source, and only during times of famine due to their bitter flavor.
The two most common types of catalpas are the hardy catalpa, which you’ll find in the northeastern as well as southwest regions of the U.S., and the southern catalpa, which grows along the southern coastline states.
A southern cultivar called "Aurea" is popular; it erupts in spring with bright yellow leaves that later turn a vivid green. Another species, the Cataola Farges catalpa, is native to China. It produces speckled flowers instead of white or cream blooms.