Catalpa, a shade tree with amazing orchid-like blooms

Catalpa tree

Catalpa is a true garden-enhancing tree. It offers unique shade foliage & flowers.

A summary of key Catalpa facts

NameCatalpa
FamilyBignoniaceae
Type – Tree

Height – 26 to 32 feet (8 to 10 meters)
Exposure – Full sun

Soil type: ordinary  –   Leafage: deciduous   –   Blooming: mid-summer

This fast-growing tree is also very hardy in winter.

How to plant catalpa

Catalpa is an easy tree to grow. It will settle in properly in any type of soil, even though, as for most trees, it prefers well-draining soil.

Mature Catalpa treeThe Orchid flower tree is extremely ornamental: in spring and summer, bright green leaves and nice flowers strike home. In fall, leaves turn a beautiful yellow hue. Try to find a spot for it apart from other trees so you can highlight its beauty.

This tree loves sunlight, which makes it an excellent shade tree.

  • Note that in winter, it fears excess water.
  • Favor planting your tree in fall to promote root growth before the winter frost spell set in.

Catalpa is a fast grower, which makes it ideal if you’re planning a shaded spot in the garden to savor in only a few year’s time.

Pruning and care for Catalpa

Though Catalpa will do perfectly fine without any pruning at all, it’s possible to prune it now and then for maintenance.

  • Catalpa pruningBest prune after leaves have fallen, or at the end of winter (when it doesn’t freeze hard any more).
  • Remove lower branches to keep them from touching the ground.
  • Eliminate dead branches and any that are twisting towards the inside of the tree.
  • Try to keep its beautiful, roundish shape as it gets older.

Indeed, Catalpa starts growing with a thin, upright figure that tends to round off with age.

  • Make sure the tree has plenty of space to grow.
  • The natural shape will always be taller than it is wide.

Caring for Catalpa

If it’s properly settled in, you can go for years without caring for the tree at all.

Caring for catalpaPerhaps only a little watering in summer during the first and second year will help it spread its roots, depending on the climate and weather.

  • Water during the first 2-3 years in hot weather.
  • Watering in the evening is more effective and lets plants absorb more water.

In dryer areas, mulch the tree around the trunk and all the way to where midday sun lays shade.

  • This is called the drip line, and it’s where roots are most active.
  • Mulch provides them with needed nutrients and moisture.
  • Mulch will help avoid leaf scorch during particularly hot and dry summers.

Learn more about Catalpa

Though there are several species within the Catalpa genus, the one you’re likely to come across it Catalpa bignonioides.

Native to North America and Asia, Catalpa is a wonderful tree thanks to its blooming shown in the picture above/right. It also works wonders as a cool shade tree.

Catalpa flowers

Spectacular and abundant flowers appear in June, signaling the time to start taking advantage of the shelter Catalpa provides from scorching heat.

  • The flowers are very surprising for such a tall tree. They’re similar to those of orchid or iris.
  • After the flowers, long seed pods form that dangle from the tree, looking quite like string beans on the vine.

These bean-like pods are what gave the tree its name: in the Cherokee language, the word ‘Catalpa’ is a type of bean plant.

Growth is rapid, and will speed up even more if planted in a warm spot.

Catalpa diseases and pests

Three main diseases may affect a weakened Catalpa tree. These are all fungal diseases.

Verticilium wilt on Catalpa

Diseases pests catalpaVerticilium wilt – Often fatal. Purple-gray streaks appear on wood when a branch is snipped. Leaves wilt, usually along an entire branch or along the sap-flow to one side of the tree.

  • Using high-nitrogen natural fertilizers is a great help to help your catalpa fight the fungus off.
  • A growth spurt might succeed in “burying” the fungus under new wood.
  • This is because the fungus has trouble crossing over radially through wood. It prefers spreading up and down along the tree.

Powdery gray or white dust on Catalpa leaves

  • Powdery mildew – As may appear on oak trees in warm, moist weather. Dusty white powder appears leaves near leaf veins.

Spots on Catalpa leaves

Leaf spot – Many possible culprits here. Usually the main fungus is Anthracnose, caused by Gloeosporium catalpae, but others also may appear.

Smart tip about Catalpa

During the first few years, spread mulch at the base of the tree to stimulate its growth.


Images: CC BY 2.0: Catherine Fraser, CC BY-SA 2.0: Ross Dunn; Pixabay: Hans Braxmeier, Светлана Бердник, James DeMers, Linda Long, Joel Tretheway