Tree · Moraceae
Mulberry
Morus rubra
Give it full sun and room to spread, and the mulberry hands you berries by the bucketful every early summer.
Full sun
Every 7–21 days
USDA 4–9
25–60 ft · 7.6–18.3 m
Overview
A mulberry is a fast, generous shade tree that pays you back in fruit. It belongs to the fig family and grows large, reaching 25 to 60 feet (7.5 to 18 m) tall with a broad, spreading crown. The red mulberry is native to the eastern US, while the white and black species came from Asia, and all of them ripen sweet, blackberry-like fruit in early summer.
What makes a mulberry easy is also what makes it a handful. It shrugs off cold down to -29°F (-34°C), takes drought once it's grown, and crops so heavily that birds scatter seedlings across the neighborhood. The fallen fruit stains pavement a deep purple, so where you plant it matters as much as how you grow it.
Pick the right spot and a mulberry needs almost nothing from you. Give it sun, deep soil, and space well clear of patios and paths, and it settles in for decades. Just know that the white mulberry has turned invasive across much of the US, so the native red mulberry or a named cultivar is the safer choice.
Care
The short version: full sun, deep well-drained soil, and plenty of room to spread. Water young trees through their first seasons, prune only in deep winter, and site the tree well away from anything the staining fruit could ruin.
Light
Mulberries crop best in full sun, though they'll take partial sun or light shade. More sun means more fruit and an open canopy that dries fast after rain, which keeps mildew at bay.
Water
Water a young tree deeply about once a week while it settles in. Once established, a mulberry is quite drought tolerant and only needs a drink during a long dry spell.
Soil
Give it deep, well-drained loam with plenty of organic matter. It puts up with clay or sand but sulks in thin, poor ground, and it's easygoing about pH anywhere from 5.5 to 7.5.
Temperature
A mulberry is remarkably hardy, taking cold to -29°F (-34°C) and heat up to 104°F (40°C). That range lets it grow comfortably across USDA zones 4 through 9.
Humidity
Average outdoor humidity, roughly 30% to 70%, suits it fine, so there's nothing to manage here. Good airflow through the canopy does more good than any number, since it keeps the leaves dry.
Feeding
Mature mulberries rarely need feeding and often crop better without it. If a young tree seems sluggish, a light balanced fertilizer or compost in early spring is plenty, since overfeeding only pushes weak, floppy growth.
Pruning
Prune only when the tree is fully dormant in late winter, or the cuts bleed sap heavily. Take out dead, crossing, or crowded branches and shape young trees, and keep your cuts under about 2 inches across.
Repotting
A mulberry is a landscape tree that lives in the ground, so it isn't repotted. Move a young or container-grown tree only while it's dormant, and watch for roots circling the pot or growth that stalls in spring.
Size & spacing
Expect a big tree, 25 to 60 feet (7.5 to 18 m) tall with a crown spreading 35 to 40 feet (10.5 to 12 m) wide. Give it that much open room, well away from buildings, paths, and other plantings.
When to plant
Mulberries follow the rhythm of the seasons. Plant a young tree in spring once the frost has passed, or set it out in fall while it sleeps. The flowers open in April and May, and the fruit ripens through May and June, stretching into summer on some types.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: Spring after the last frost, or in fall while the tree is dormant
- Harvest: Blooms April-May; fruit ripens roughly May-June (into summer for some types)
Hardiness
USDA hardiness zones: 4–9
Temperature: down to -34°C
Troubleshooting
A mulberry is tough, so most of its trouble is mess and pests rather than disease. Watch the trunk for borers, the leaves for mildew, and the ground for stains and stray seedlings. Match what you see below, then act while it's still a small job.
Wilting branches with sawdust and small holes near the trunk
These are the tracks of a borer tunneling under the bark, and you'll spot round exit holes, oozing, and powdery frass where it works. Cut out and burn the infested limbs, then keep the tree strong with steady water and mulch so it can wall off new attacks. Most of all, keep mowers and trimmers away from the trunk, since fresh bark wounds are exactly where the beetle lays its eggs.
Fix:
- Prune out and destroy infested limbs
- Keep the tree vigorous with proper water and mulch
- Avoid bark wounds that invite egg-laying
A white, dusty film across the leaves in late summer
This is powdery mildew, a surface fungus that rubs off when you wipe a leaf and coats both the top and the underside. It rarely does lasting harm to a big tree, so thin out crowded growth to let air move and rake up the fallen leaves to clear the spores. A sunny, open spot and dry foliage keep it from coming back.
Fix:
- Improve air circulation by thinning crowded growth
- Rake and remove fallen infected leaves
Purple-stained pavement and seedlings popping up everywhere
A heavy crop is the price of a mulberry, and the dropped berries stain everything beneath the canopy while birds scatter the seed far and wide. Pull the volunteer seedlings while they're small and easy, and clean up fallen fruit before it sets. The real cure is placement, so keep a fruiting tree well back from patios, driveways, and walkways, and reach for a fruitless cultivar only where pollen-allergy rules allow it.
Fix:
- Hand-pull volunteer seedlings while young
- Site away from patios, driveways, and walkways
- Choose a fruitless cultivar only where allergy bans do not apply
Toxicity
The ripe fruit is sweet and safe for people and pets alike, which is the whole appeal of the tree. The catch is the rest of it. Unripe green berries and the milky sap in the leaves and stems can irritate skin and unsettle a stomach, so keep grazing animals and curious children away from the green parts.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats Mild
Ripe berries do a cat no harm, but the milky sap and green unripe fruit can leave it drooling or with a brief bout of vomiting. Keep the chewing to a minimum and the upset stays minor.
Dogs Mild
A dog can snack on the ripe fruit without trouble. Eat enough unripe berries or chew the sappy leaves, though, and you may see soft stools or a touch of vomiting that passes on its own.
Horses Mild
Ripe windfalls are fine in moderation. Grazing on leaves heavy with sap or on green fruit can loosen the gut and dull the appetite for a day or so.
Rabbits Mild
Small amounts of ripe fruit make a safe treat, but a rabbit's gut is sensitive, so unripe berries and sappy leaves can bring on soft stools. Go easy and watch for any digestive upset.
Livestock Mild
Cattle, goats, and sheep eat fallen mulberries with no harm. A big helping of green fruit or sap-laden leaves may cause passing diarrhea, and in real quantity the unripe berries can act as a mild intoxicant.
Birds Mild
Birds flock to ripe mulberries and come to no harm at all, which is half the reason the tree spreads so widely. Only the green, unripe berries might unsettle a stomach.
People Ripe fruit safe
Ripe mulberries are a sweet, safe fruit eaten fresh or baked. Skip the unripe green berries and avoid the milky sap, which can irritate skin and, in quantity, upset the stomach or even cause hallucinations.
Ripe berries are safe, but unripe green or white berries and the milky sap of leaves and stems can cause mild gastrointestinal upset, and the sap is a mild skin and GI irritant.
Varieties
Three species and a few hybrids cover most of what you'll find for sale. Knowing them apart helps you choose the right tree and steer clear of the invasive one.
Morus rubra (red mulberry)
The native of the eastern US, it carries dull, non-glossy leaves and bears dark red-to-purple fruit.
Morus alba (white mulberry)
Brought over from Asia for silkworms, it has glossy leaves and turns invasive across much of the US, where it hybridizes with the native red mulberry.
Morus nigra (black mulberry)
It bears the largest, richest-flavored fruit of the three but is the least cold hardy.
Illinois Everbearing
A productive cross of M. alba and M. rubra, this cultivar fruits over a long, heavy season.
Companions
A mulberry works best as a decoy for hungry birds and worst as a neighbor to anything that needs sun or clean ground beneath it.
Plant near
Cherries and blueberries: Birds strongly prefer mulberries, so a mulberry can act as a decoy that draws them away from other fruit crops.
Clover or other low groundcover: A living groundcover suppresses weed seedlings and adds organic matter under the canopy.
Keep apart
Vegetable and flower beds: Dense shade, greedy shallow roots, and staining fruit drop make underplanting and nearby beds difficult.
How to propagate
You can multiply a mulberry from a cutting, a graft, or a seed, and the right method depends on whether you want a copy of a named tree or simply more trees.
Stem cuttingsEasy
Hardwood cuttings in late winter; softwood cuttings in early summer · About 4-8 weeks to root
Take hardwood cuttings in late winter or softwood cuttings in early summer, and most will root in about 4 to 8 weeks. White mulberry strikes readily this way, while red and black mulberry are slower and harder to coax into root.
GraftingModerate
Late winter to early spring (whip or bark graft) · One growing season
Grafting is the standard way to carry a named fruiting cultivar or a hard-to-root species onto tough seedling rootstock. Make the whip or bark graft from late winter into early spring, and a successful union takes hold over a single growing season.
SeedModerate
Sow after 1-3 months of cold stratification · Several years to first fruit
Give the seed 1 to 3 months of cold stratification before sowing, then settle in for the long wait, since a seedling takes several years to fruit. The offspring come out variable, and white mulberry in particular self-seeds aggressively wherever birds drop the fruit.
Myths
Fruitless male mulberries make a clean, problem-free shade tree.
Going fruitless trades one mess for another. The male trees, usually Morus alba, throw off huge clouds of allergenic pollen, and some cities such as Albuquerque restrict or ban them outright to protect air quality.
Every part of the mulberry is poisonous.
Not so. The ASPCA lists mulberry as non-toxic and the ripe fruit is good to eat. Only the unripe berries and the milky sap cause trouble, and even then it's a mild, short-lived stomach upset.