Tree · Bignoniaceae
Northern Catalpa
Catalpa speciosa
A tough native shade tree that erupts in showy white flowers and races skyward almost anywhere.
Full sun
Every 7–21 days
USDA 4–8
40–70 ft · 12.2–21.3 m
Overview
Northern catalpa rewards anyone who wants results fast. It shoots up into a real shade tree in just a few seasons, and every late spring it bursts into showy white flowers shaped like little orchids that stop people in their tracks. By fall it dangles long, slender pods, the trick behind nicknames like cigar tree and Indian bean tree, and the heart-shaped leaves grow big and bold all season long.
What makes it so much fun to grow is how little stands in its way. It powers through wet ground, dry ground, clay, poor soil, and city grime, and it keeps climbing across a wild swing from -29°F to 100°F (-34°C to 38°C). That mix of grit and speed is exactly why it thrives in tough spots that defeat pickier trees, so it pays off where planting feels like a gamble.
It does come with a couple of quirks to plan for. The big leaves, spent flowers, and long pods pile up, and the brittle wood snaps in wind and ice. Hand it open room away from patios and walks, shape it young into a solid frame, and it charges ahead to deliver decades of quick, generous shade.
Care
The short version: hand it full sun to part shade and just about any soil, wet or dry, and it takes off on its own. It almost never needs feeding or extra water once it settles, so the real work is pruning it young for a strong frame and parking it where falling limbs and litter won't get in the way.
Light
Catalpa thrives in full sun and still takes part shade in stride. Pour on the sun and it flowers harder and builds a denser, sturdier crown, while a shadier spot still pushes up a healthy tree.
Water
Once it digs in, this tree powers through both seasonal flooding and drought, so it rarely needs watering at all. Young trees are the exception and want steady moisture through their first year or two while the roots reach down. Let the top half of the soil dry between drinks.
Soil
Hardly any tree cares less about soil. Catalpa loves a moist, fertile loam with some organic matter, but it tears ahead just as well in clay, soggy low spots, dry poor ground, or rough urban dirt.
Temperature
This cold-hardy, heat-tough tree romps across USDA zones 4 to 8 and rides out a range from -29°F to 100°F (-34°C to 38°C). Plant it once and temperature drops right off the list of things to manage.
Humidity
Everyday outdoor humidity suits it fine, so skip chasing a number. Good air movement counts for more, since open airflow shuts out the leaf-spot and mildew fungi before they can take hold.
Feeding
This adaptable native barely needs feeding to keep charging. If growth looks weak, hit it with one balanced, general-purpose tree fertilizer in spring, and most years you can skip feeding entirely.
Pruning
Prune in late winter to early spring to clear out dead, weak, or crossing branches and to drive a strong central leader. The wood is brittle and snaps easily, so early structural pruning pays off big for the life of the tree.
Repotting
Catalpa wants the open ground, not a pot, so repotting rarely comes up. If you are running a young one in a container, bump it up the moment roots circle inside, burst through the drainage holes, or water runs straight through.
Size & spacing
This tree gets big, rocketing to 40 to 70 feet (12 to 21 meters) tall and spreading 20 to 50 feet (6 to 15 meters) across. Give it plenty of open room, well clear of buildings, walks, and power lines.
When to plant
Catalpa launches easily and isn't fussy about timing. Get it in the ground in spring once the last frost clears, or plant in fall, then look forward to the big payoff, the white flower panicles in May and June, with the long pods racing in behind them all 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
Catalpa shrugs off most trouble like a champ, and nearly everything that hits it is cosmetic rather than serious. The one to learn fast is verticillium wilt, since it has no cure. Match what you spot below before you grab any treatment.
Wilt striking fast, branches dying back on one flank
This is verticillium wilt, a soilborne fungus that clogs the wood from the inside, and no chemical will cure it. Cut a wilting branch and hunt for brown or greenish streaks under the bark to confirm it. Prune out the affected limbs, keep the tree well watered to hold its vigor, and if it dies, skip replanting a susceptible species in 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
Limbs snapping and leaves shredding when storms hit
Catalpa wood is naturally brittle, so wind, ice, and hail break limbs and shred the big leaves. After a storm, scan for snapped or hanging branches and prune them off cleanly. Train young trees to a strong central leader early, and plant where falling limbs won't threaten a patio or walk.
Fix:
- Prune cleanly to remove broken or hanging limbs
- Develop a strong central leader and good branch structure with early structural pruning
Leaves vanishing fast, whole canopy stripped by summer
Meet the catalpa sphinx caterpillar, the catalpa worm, which feeds on nothing but catalpa. The caterpillars swarm and can strip a tree in mid to late summer, but the tree bounces right back and re-leafs without missing a beat. Handpick them off a small tree if you want, or leave them be, since plenty of 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 chalky white film or dark spots dotting the leaves
These are powdery mildew and leaf spot fungi, sometimes joined by twig blight that knocks out small shoots. Bad mildew yellows the leaves and drops them early, but the damage stays cosmetic and rarely calls for a fungicide. Rake up and bin the fallen leaves and open the canopy to get 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
Pet owners can dive in with confidence, because catalpa is not toxic. It never landed on the ASPCA poison-plant lists, and the long bean-like pods, while not for eating, pose no poisoning hazard. The only thing to watch is the foliage, which can leave sensitive skin a little itchy, so pull on gloves for a big 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
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 they are safe around it.
Rabbits Safe
No part of the leaves or pods carries a toxin for rabbits, so a quick nibble is perfectly safe.
Livestock Safe
Goats, cattle, and sheep can browse right around the tree with no danger, since catalpa poses no known poisoning risk.
Birds Safe
Birds come to no harm from the foliage or the long pods.
People Safe
People are perfectly safe near it, even if the pods aren't edible and handling the foliage can make sensitive skin itch, so pull on gloves before a big tidy-up.
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 turn up in yards and along streets, from the towering northern and southern species to a couple of selections grown for their shape or color. Here are the ones worth chasing down by name.
Catalpa speciosa (Northern catalpa)
The bigger, hardier of the two main species, rocketing up tall and upright with green-scented leaves and laughing off cold down through zone 4.
Catalpa bignonioides (Southern catalpa)
Compact and round-crowned, it puts out foul-smelling leaves and flowers dressed in bolder purple spots that break open a little later than its northern cousin.
Catalpa bignonioides 'Nana' (Umbrella catalpa)
A dwarf, non-flowering form grafted onto a standard trunk so it builds into a dense, rounded umbrella of a head.
Catalpa bignonioides 'Aurea'
A golden-leaved selection grown for its bright yellow to yellow-green foliage.
How to propagate
Catalpa multiplies with gusto, so go ahead and sow the seed straight from the pods or strike a cutting off a tree you already love.
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 fastest, easiest way in. Grab it from the long pods in fall and sow from late winter into spring, no soaking or chilling required. It sprouts readily, and because the tree grows so fast it fills out to landscape size within a season or two.
Stem cuttingsModerate
Softwood cuttings in early summer or hardwood cuttings in the dormant season. · 1 season to root
Cuttings work great too, taking softwood in early summer or hardwood while the tree is dormant, and they root in about a season. Root cuttings also do the job. Named forms like 'Nana' come grafted rather than struck from cuttings, since they don't come true on their own roots.
Myths
Let catalpa worms loose and they'll gobble every leaf and doom the tree.
The catalpa sphinx caterpillar can strip a tree bare, but it powers right back and re-leafs, even after the same thing happens several years running. The defoliation looks alarming but does no lasting harm, so you rarely need to lift a finger.
Watch out, the long pods will poison your pets.
Catalpa keeps clear of every ASPCA poison-plant listing and ranks as non-toxic. The pods, though inedible, bring no poisoning danger to a cat or dog roaming nearby.