Tree · Cornaceae
Kousa Dogwood
Cornus kousa
A small tree that gives you star-shaped blooms, edible fruit, and peeling bark across all four seasons.
Full sun
Every 5–10 days
USDA 5–8
15–30 ft · 4.6–9.1 m
Overview
Kousa dogwood earns its place in a garden by changing with every season. Late spring brings a heavy show of pointed, star-shaped bracts, and unlike the native flowering dogwood it opens after the leaves are out, so the blooms float against a green backdrop. By late summer it hangs with pinkish-red fruit that birds love and people can eat.
It stays modest in size, reaching 15 to 30 feet (4.6 to 9.1 m) tall and about as wide, with a vase shape in youth that rounds out with age. The growth is slow, so it never overwhelms a small yard. As the trunk matures it sheds patches of bark to leave a mottled, camouflage pattern that carries the tree through winter when nothing else is going on.
Gardeners often reach for it as a tougher stand-in for Cornus florida. It resists the anthracnose and borers that plague the native dogwood, asks little once it's settled in, and handles cold down to -20°F (-29°C). Give it decent soil and steady moisture and it mostly takes care of itself.
Care
The short version: full sun to part shade in rich, slightly acidic, well-drained soil, kept evenly moist through the heat of summer. Mulch the roots, prune almost never, and let this slow grower settle in at its own pace.
Light
Kousa dogwood does best in full sun to part shade. Full sun gives the heaviest bloom, but in hot regions a little afternoon shade spares the leaves from scorching in midsummer.
Water
Keep the soil at a steady, medium moisture, watering every 5 to 10 days and more often through a hot, dry spell to head off leaf scorch. Once established it stands up to drought better than the native dogwood, though it never wants to sit in waterlogged ground.
Soil
Plant in rich, humusy, well-drained loam on the acidic to neutral side, ideally a pH of 5.5 to 7.0. Working in compost and topping with an acidic organic mulch keeps the roots cool and fed.
Temperature
The tree is hardy across a wide range, from -20°F to 95°F (-29°C to 35°C), which covers USDA zones 5 through 8. It takes hard winters in stride and only struggles where summers turn relentlessly hot and dry.
Humidity
Ordinary outdoor humidity suits it fine, so there's no figure to chase. What matters more is air movement, since crowded, stagnant growth is what invites powdery mildew onto the leaves.
Feeding
Feed once in early spring with a balanced slow-release fertilizer, or simply top-dress with acidic compost or mulch. This slow grower has modest needs and doesn't want to be pushed.
Pruning
Prune as little as possible. Take out only dead, damaged, or crossing branches, and do it just after flowering in late spring to early summer so you don't cut off next year's buds.
Repotting
A kousa dogwood is rarely grown in a container long-term, so repotting almost never comes up. If one is potted and the roots start circling or pushing through the drainage holes, move it to a larger container or, better, into the ground.
Size & spacing
Expect a mature tree of 15 to 30 feet (4.6 to 9.1 m) tall with a spread to match. Give it that much open room so the broad, rounded crown can fill out and air can move through the branches.
When to plant
Kousa dogwood is a woody tree planted once and kept for decades. Set it out in spring or fall so the roots can take hold before the next round of heat or hard frost, and expect the bloom in late spring with edible fruit ripening from late summer into early fall.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: spring or fall
- Harvest: Blooms late spring to early summer (May to June), after leaves emerge; pinkish-red edible fruit ripens late summer to early fall.
Hardiness
USDA hardiness zones: 5–8
Temperature: down to -29°C
Troubleshooting
Most kousa dogwood trouble is written on the leaves, and the cause is usually the site or the weather rather than the tree. Tell summer scorch apart from the two leaf-spotting fungi and you'll know whether to reach for the hose or the rake. Match what you see below, then act before it spreads.
Browned, crisp leaf edges in the heat of summer
This is leaf scorch, and it shows up when a tree in a hot, sunny spot can't pull up enough water to keep its leaves hydrated. Young trees with shallow roots feel it first. Water deeply through dry spells, lay down a 2 to 3 inch (5 to 8 cm) mulch ring to hold moisture, and give the tree some afternoon shade where summers run hot.
Fix:
- Provide deep, regular watering during heat and drought
- Apply a 2-3 inch organic mulch layer to conserve soil moisture and keep roots cool
- Site in partial afternoon shade in hot climates
A dusty white film coating the leaves
That coating is powdery mildew, a fungus that takes hold in humid air, deep shade, and still, crowded growth. It can warp the leaves but rarely does lasting harm. Thin the canopy and space plants so air moves freely, pull off badly coated leaves, and reach for a labeled fungicide only when an outbreak gets out of hand.
Fix:
- Improve air circulation by thinning and proper spacing
- Remove and dispose of affected foliage
- Apply a labeled fungicide if infection is severe
Small angular brown to purple spots dotting the leaves
These angular, dark-edged flecks are septoria leaf spot, a fungus that flares up later in the season after long stretches of wet foliage. Unlike scorch, it spots the leaf rather than browning the margin. Rake up and bin fallen leaves so spores don't overwinter, keep water off the foliage, and treat with a labeled fungicide only if the tree starts dropping leaves in earnest.
Fix:
- Rake and dispose of fallen infected leaves
- Avoid overhead watering and wetting foliage
- Apply a labeled fungicide only if defoliation is significant
Toxicity
Good news on every front here. Kousa dogwood is non-toxic to pets, livestock, and people, and its ripe pinkish-red fruit is actually good to eat. There's no part of this tree you need to fence off or worry about a curious pet sampling.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats Safe
No part of the tree is toxic to cats. A cat that nibbles a leaf might get a brief, mild stomach upset, the same as with any non-food plant, and nothing more.
Dogs Safe
Dogs can chew the leaves, bark, or fallen fruit without any real risk. At most a gulped mouthful brings a passing bit of tummy trouble that settles on its own.
Horses Safe
Horses come to no harm from this tree, foliage and fruit alike. There's nothing here that warrants fencing it off from a paddock.
Rabbits Safe
Rabbits can browse the leaves safely. As with any new green, introduce it slowly so a sudden change of diet doesn't loosen their digestion.
Livestock Safe
Cattle, goats, and sheep can graze around the tree without trouble, since it carries no toxin that affects them.
Birds Safe
Birds feast on the ripe fruit and help spread the seed. It's a welcome food source rather than a hazard.
People Safe
The ripe pinkish-red fruit is good to eat, sweet and soft inside, and the rest of the tree poses no danger. The thin skin and gritty seeds are usually left behind.
No special handling required; ingestion of plant material may rarely cause mild, transient gastrointestinal upset as with any non-food plant.
Varieties
Most kousa dogwoods sold are named selections chosen for their flowers, foliage, or toughness. These are the ones worth knowing by name.
Milky Way
A heavy-flowering selection, often listed under var. chinensis, that smothers itself in creamy-white bracts and follows with a generous crop of fruit.
Wolf Eyes
A compact, slow grower whose green leaves carry crisp white margins, making it the pick for smaller gardens and brighter foliage.
Satomi
Stands apart for its deep pink to rose bracts instead of the usual white.
Cornus × rutgersensis (Stellar series)
These Rutgers hybrids of Cornus florida and Cornus kousa, such as Aurora, Constellation, and Stellar Pink, were bred to shrug off anthracnose and borers.
How to propagate
You can multiply kousa dogwood several ways, from slow and variable seed to the layering trick that asks almost nothing of you. How you go about it depends on whether you need an exact copy of a named tree.
SeedModerate
Sow cleaned seed in fall or after cold-moist stratification in late winter. · Several years to reach flowering size
Clean the pulp off the seed and either sow it in fall or give it a cold-moist stratification before sowing in late winter, which wakes it up to germinate. Be patient, since a seedling takes several years to reach flowering size. The catch is that seedlings come up variable, so you can't count on matching the parent tree.
Stem cuttingsModerate
Take softwood to semi-hardwood cuttings in late spring to summer. · One growing season to root and establish
Take softwood to semi-hardwood cuttings from late spring into summer, dip them in rooting hormone, and keep them under mist. They root over a single growing season, and kousa cuttings take more readily than those of many other trees.
GraftingDemanding
Graft named cultivars onto seedling rootstock in late winter or summer. · One to two seasons to establish union
This is the demanding route, done by grafting or budding a named cultivar onto seedling rootstock in late winter or summer. The union knits together over one to two seasons. It's how nurseries keep cultivars true to type, since the offspring of seed won't be.
LayeringEasy
Layer low flexible branches in spring. · One to two growing seasons to root
The easiest method for a home gardener is to layer a low, flexible branch in spring by pinning it to the ground until it roots. It takes one to two growing seasons to root, after which you can sever it and move the new plant.
Myths
Kousa dogwood catches anthracnose and borers just as badly as the native flowering dogwood.
Cornus kousa holds up far better against both dogwood anthracnose and the dogwood borer than Cornus florida does. It's the tree to plant where anthracnose has been a problem, which is exactly why it's so often recommended as a replacement.
The red raspberry-like fruit is poisonous and shouldn't be eaten.
The pinkish-red fruit is perfectly edible, soft and sweet inside once fully ripe. Birds and other wildlife eat it too, so it does double duty as food and as a draw for the garden.