Tree · Bignoniaceae
Northern Catalpa
Catalpa speciosa
A grand native shade tree whose showy white flowers set the scene and grow fast almost anywhere.
Full sun
Every 7–21 days
USDA 4–8
40–70 ft · 12.2–21.3 m
Overview
Some trees anchor a whole property, and northern catalpa is one of them. For a few weeks each late spring it turns into the centerpiece of the garden, dressed in showy white flowers that read like orchids from across the lawn, and by autumn it trades them for long, slender pods that gave it the easy nicknames cigar tree and Indian bean tree. Plant it where you want a yard to feel established, and it obliges fast.
Its real luxury is how undemanding it is. This is a tree for the spot nothing else will take, the wet corner, the dry verge, the hard ground along a city street, holding its own through a climate that runs from -29°F to 100°F (-34°C to 38°C). That ease is what makes it such a generous backdrop, throwing cool, dependable shade over a patio set or a stretch of lawn while you get on with the day.
It does ask for a little forethought in placement. The big leaves, spent flowers, and long pods come down as the season turns, and the brittle wood can drop a limb in a storm, so this is a tree for the open part of a property rather than over the dining table outdoors. Site it with room to breathe, shape it young, and it settles into the role of shade tree for decades.
Care
The short version: give it full sun to part shade and almost any soil, wet or dry, and it largely takes care of itself. It rarely asks for feeding or extra water once settled, so the real work is pruning it young for a handsome frame and placing it where the falling limbs and seasonal litter stay out of the living areas.
Light
Catalpa looks its best in full sun, though it takes part shade in stride. A sunny position rewards you with heavier flowering and a fuller, more sculptural crown, while a shadier corner still gives you a healthy tree to round out a planting.
Water
Once it has settled into a spot, this tree handles both seasonal flooding and drought, so it asks almost nothing of the watering can. Newly planted trees are the exception and appreciate steady moisture through their first year or two. Let the top half of the soil dry between drinks.
Soil
Few trees are easier to place when it comes to ground. Catalpa favors a moist, fertile loam with some organic matter, yet it settles just as readily into clay, low wet ground, dry poor soil, or the rough conditions of a city lot.
Temperature
This is a tree for nearly any climate in its range, at home across USDA zones 4 to 8 and unbothered by a swing from -29°F to 100°F (-34°C to 38°C). Once it is in the ground, the weather is one less thing to manage in the garden.
Humidity
Ordinary outdoor air suits it perfectly, so there is no number to fuss over. What helps the look is good air movement, an open setting that keeps the leaf-spot and mildew fungi from taking hold and the canopy looking clean.
Feeding
This easygoing native rarely needs feeding, which keeps it off the maintenance calendar. If growth looks thin, a single balanced, general-purpose tree fertilizer in spring is plenty, and most years you can leave it be.
Pruning
Prune in late winter to early spring to take out dead, weak, or crossing branches and to guide a strong central leader. Since the wood is brittle, that early shaping is what gives the tree the clean, dependable silhouette it will hold for decades.
Repotting
Catalpa belongs in the landscape rather than a container, so repotting rarely comes up. If you are growing a young one in a pot for a season, move it up when roots circle inside, push through the drainage holes, or water runs straight through.
Size & spacing
This is a large tree with real presence, reaching 40 to 70 feet (12 to 21 meters) tall and spreading 20 to 50 feet (6 to 15 meters) across. Give it generous open ground, well clear of the house, walkways, and power lines, so it can fill the scene the way it is meant to.
When to plant
There is no rush and no precise window to hit. Set it out in spring once frost has passed, or in fall, then look forward to the headline moment, the white flower panicles in May and June, with the long pods trailing in behind them to carry the look through summer.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: Late winter to early spring; seed needs no special pretreatment.
- Plant: Spring after the last frost, or in fall.
- Harvest: Showy white orchid-like flower panicles in late spring to early summer (May to June), followed by long bean-like seed pods.
Hardiness
USDA hardiness zones: 4–8
Temperature: down to -34°C
Troubleshooting
As a centerpiece tree, catalpa is reassuringly low-drama, and most of what it runs into is cosmetic rather than serious. The one worth knowing is verticillium wilt, which has no cure. Match what you are seeing below before reaching for any treatment.
A sudden wilt creeping across one flank of the tree
Verticillium wilt is a soilborne fungus that clogs the wood from within, and there is no chemical cure. To confirm it, cut a wilting branch and look for brown or greenish streaks under the bark. Prune out the affected limbs, keep the tree well watered to hold its vigor, and if it succumbs, choose a different, resistant species for that spot.
Fix:
- Prune out and dispose of affected branches
- Keep the tree vigorous with proper watering, as there is no chemical cure
- Avoid replanting susceptible species in the same soil if a tree dies
Split limbs and frayed leaves in a storm's wake
Catalpa wood is naturally brittle, so wind, ice, and hail break limbs and tatter the big leaves. After a storm, look over the tree for snapped or hanging branches and prune them off cleanly. Training a young tree to a strong central leader and placing it where a falling limb won't reach a patio or walk keeps the setting safe and the look intact.
Fix:
- Prune cleanly to remove broken or hanging limbs
- Develop a strong central leader and good branch structure with early structural pruning
Ragged, eaten foliage stripping the summer canopy
This is the catalpa sphinx caterpillar, the catalpa worm, which feeds on nothing but catalpa. The caterpillars cluster and can strip a tree in mid to late summer, yet it re-leafs and recovers, so the bare patch is only a passing look. Pick them off a small tree if you prefer it tidy, or leave them, since many anglers prize them as fish bait.
Fix:
- Handpick caterpillars from small trees, or simply tolerate them since trees easily re-leaf
- Harvest them as fish bait, for which catalpa worms are prized
- Apply a labeled caterpillar control such as Bt or a recommended insecticide only for heavy infestations on small or young trees
A pale powdery bloom or spotting dulling the leaves
These come from powdery mildew and leaf spot fungi, sometimes with twig blight that kills off small shoots. Heavy mildew can yellow the leaves and drop them early, but the effect stays cosmetic and rarely calls for a fungicide. Rake up and bin the fallen leaves and open the canopy to keep the air moving.
Fix:
- Rake and dispose of fallen infected leaves
- Improve air circulation
- These foliar problems are largely cosmetic and rarely require fungicide
Toxicity
For a household with pets underfoot, catalpa is an easy choice, since it is not toxic. It never appeared on the ASPCA poison-plant lists, and the long pods, while not for eating, are not a poisoning hazard. The only note is the foliage, which can leave sensitive skin a little itchy, so keep gloves on hand for a big seasonal cleanup.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats Safe
Catalpa isn't on the ASPCA toxic list, so a curious cat that bats at a fallen pod is in no danger.
Dogs Safe
There's no poisoning hazard here. A dog that chews a stray pod might get a mild stomach upset from the bulk, but the tree itself is not toxic.
Horses Safe
Catalpa carries no known toxin for horses and isn't on any poison-plant lists, so it is safe near a paddock.
Rabbits Safe
Nothing in the foliage or pods will harm a rabbit, so a stolen nibble does no damage.
Livestock Safe
Grazing animals like goats, sheep, and cattle can feed around a catalpa safely, since it poses no recognized poisoning threat.
Birds Safe
Birds come to no harm from the foliage or the long pods.
People Safe
The tree is safe to live alongside, though the pods are inedible and the foliage can leave sensitive skin a little itchy, so wear gloves for a big cleanup.
The long seed pods and large leaves create heavy litter, and the foliage can cause minor contact dermatitis in sensitive people, so wear gloves when handling.
Varieties
A handful of catalpas find their way into gardens and along avenues, from the stately northern and southern species to a couple of selections chosen for the shape or color they bring to a planting. These are the ones worth knowing by name.
Catalpa speciosa (Northern catalpa)
The larger, hardier of the two species, growing tall and upright with green-scented leaves, and untroubled by cold down through zone 4.
Catalpa bignonioides (Southern catalpa)
A more compact, rounded form whose leaves give off a rank odor, carrying blooms marked with denser purple spotting that arrive slightly later in the year.
Catalpa bignonioides 'Nana' (Umbrella catalpa)
A dwarf, non-flowering form grafted onto a standard trunk so it forms a dense, rounded umbrella of a head, a tidy accent for a formal spot.
Catalpa bignonioides 'Aurea'
A golden-leaved selection chosen for the bright yellow to yellow-green foliage it lends a planting.
How to propagate
Catalpa is happy to give you more of itself for the rest of the garden, whether you sow seed straight from the pods or root a cutting from a tree already on the property.
SeedEasy
Collect seed from the long bean-like pods in fall and sow in late winter to spring. · 1 to 2 seasons
Seed is the simplest route. Collect it from the long pods in fall and sow from late winter into spring, with no soaking or chilling beforehand. It sprouts readily, and thanks to the tree's speed it fills out to landscape size within a season or two, ready to take its place in the garden.
Stem cuttingsModerate
Softwood cuttings in early summer or hardwood cuttings in the dormant season. · 1 season to root
Cuttings are the other option, softwood in early summer or hardwood while the tree is dormant, taking about a season to root. Root cuttings work too. Named forms like 'Nana' come grafted rather than from cuttings, since they don't come true on their own roots.
Myths
A catalpa worm infestation clears the canopy and leaves the tree for dead.
The catalpa sphinx caterpillar can strip a tree bare, and yet it leafs out again and recovers fully, even when the same thing happens several years running. The defoliation looks alarming but does no lasting harm, so the centerpiece comes back on its own with little from you.
The slender pods pose a poisoning risk to household pets.
Catalpa never turns up on the ASPCA poison lists and rates as non-toxic. Those slender pods stay inedible but carry no poisoning risk, so a cat or dog sharing the room is no cause for worry.