Shrub · Hydrangeaceae
Mock Orange
Philadelphus coronarius
Loose sprays of four-petaled white flowers open along arching canes and pour out an orange-blossom scent.
Full sun
Every 7–14 days
USDA 4–8
10–12 ft · 3–3.7 m
Overview
The signature of mock orange is its bloom: white, four-petaled flowers that open along the canes in late spring, each one crisp and simple, together pouring out a rich orange-blossom scent that carries across the garden. It is a deciduous shrub in the hydrangea family, native to southeastern Europe and Asia Minor, and it grows into a large, multi-stemmed mound of long arching canes.
The plant itself is tough beneath that delicate flower. It withstands cold down to zone 4, takes drought and wind once its roots settle, and grows in sandy, loamy, or clay soil, even where the pH runs alkaline. Sun is its one clear need, since shade thins the flowers and lets a pale mildew film form on the leaves.
Age reshapes the form. Left uncut, the canes grow leggy and twiggy, the white flowers drifting up to the tips while the lower stems stand bare. A yearly cut of the oldest canes fills the shrub back out and brings the bloom down within view, which is nearly all the work it needs.
Care
The short version: full sun for the heaviest bloom, moist well-drained soil while it establishes, and one prune right after flowering to keep an aging shrub full and fragrant.
Light
In full sun the canes carry the heaviest, most fragrant load of white flowers. Partial shade keeps the shrub growing but shifts it toward leafy green over bloom, and a pale powdery mildew tends to form on the crowded inner leaves.
Water
Keep the soil moist while the roots establish, then ease off, because a settled shrub takes drought and wind on its own and wants little extra water. A drink every 7 to 14 days is plenty in dry spells. Wet, poorly drained ground is what it will not tolerate.
Soil
Mock orange roots into sand, loam, or clay alike, so long as water drains away from the crown. A pH from 4.0 to 7.0 suits it, reaching into the alkaline range that defeats many shrubs.
Temperature
The canes and buds ride out a wide swing, from about -29°F to 100°F (-34°C to 38°C). The shrub comes through the hard freezes of zone 4 and holds its green through summer heat.
Humidity
Ordinary outdoor humidity suits it, so there is no level to manage. Air moving through the canes matters more, since still, crowded growth lets a powdery white mildew film form on the leaves.
Feeding
This vigorous shrub asks little at the root. A balanced fertilizer or a light layer of compost in spring is enough, and heavier feeding only forces soft, tender shoots that draw aphids.
Pruning
Mock orange sets its flowers on old wood, so the cuts come right after the blooms fade in early summer, never in fall or winter. As the canes age and grow bare and leggy, about a third of the oldest stems comes out at the ground each year to push fresh growth from the base.
Repotting
This is a shrub for open ground, not a pot, so repotting seldom applies. When a move is needed, the young suckers at its base lift and transplant in early spring or fall, while the plant is dormant or just breaking bud.
Size & spacing
Grown out, the arching canes reach 10 to 12 feet (3 to 3.7 m) tall and spread 8 to 10 feet (2.4 to 3 m) wide. That broad, fountaining mound needs room to arch clear of a wall or path.
When to plant
Set new plants into cool, damp soil in spring or fall. The white, four-petaled flowers open along the canes in late spring to early summer, roughly May into June, a brief flush of bloom against fresh green leaves.
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: White fragrant flowers in late spring to early summer (May to June)
Hardiness
USDA hardiness zones: 4–8
Temperature: down to -34°C
Troubleshooting
Mock orange rarely shows serious damage, and most of what marks the leaves is cosmetic. The clearer sign of trouble is a shrub carrying few flowers on bare stems, which nearly always follows pruning at the wrong time. Look closely at the symptom below and act before it sets in.
Few white flowers stranded on long, bare canes
The bloom thins when timing goes wrong, because mock orange flowers on old wood, so a fall or winter cut strips the buds set for spring. Deep shade and years without renewal leave the same bare canes. Pruning only right after the flowers fade, taking out a third of the oldest canes each year, and moving it into fuller sun bring the white bloom back low on the plant.
Fix:
- Prune only immediately after flowering, not in fall or winter
- Renewal prune by removing about one third of the oldest canes to the ground
- Move or site in fuller sun for best bloom
A pale white film dusting the leaf surfaces
The film is powdery mildew, a fungus that forms where the air sits still and the canes stand in too much shade. Cutting a few stems to open the canopy and stripping the worst leaves lifts it off. Set in full sun, where the leaves dry fast, the shrub stays clear of it.
Fix:
- Prune to open up the canopy and improve air circulation
- Remove and dispose of badly affected foliage
- Site in full sun where foliage dries quickly
Dark spots and blotches marking the green leaves
These are fungal leaf spots, dark or tan flecks that look worse than they are on this shrub. The spores overwinter in the fallen leaves, so raking them up, thinning a few canes for air, and keeping water off the foliage clear the way. The green grows back clean most years.
Fix:
- Rake and remove fallen, infected leaves
- Thin stems to improve airflow
- Avoid wetting foliage when watering
Curled, distorted new shoots massed with tiny insects
The soft-bodied insects crowding the tender tips are usually aphids, and they leave a sticky film on the young leaves. A hard jet of water knocks them off, and insecticidal soap follows only if they hold on. Pale winding trails threading inside the leaves point to leaf miners instead, and those leaves are picked and destroyed.
Fix:
- Dislodge aphids with a strong spray of water
- Use insecticidal soap if populations are heavy
- Remove and destroy mined leaves
Toxicity
The white flowers and green foliage look inviting, and they are safe, because mock orange is non-toxic in every part. Nothing in the leaves, stems, or blooms will poison a cat, dog, horse, rabbit, bird, or child. A stray mouthful brings only mild stomach upset, the same as chewing any plant.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Cats come to no harm from mock orange. A nibble at a white flower or green leaf will not poison them, though chewing any plant can leave a little drool or a brief upset stomach.
Dogs None
Dogs are unharmed by this shrub. Nothing in the green foliage or white blooms is toxic, so a stolen mouthful means no more than the odd bout of mild tummy trouble.
Horses Safe
Horses can crop the leaves near mock orange without risk. The plant holds no toxins that affect them, so it stands safely along a paddock edge or pasture border.
Rabbits Safe
Rabbits take no harm from mock orange. The green leaves and stems are non-toxic, so a rabbit that samples a low cane comes away fine.
Livestock Safe
Cattle, goats, and sheep can browse the foliage safely. Nothing in the shrub troubles ruminants, so it poses no threat where stock roam.
Birds Safe
Birds are safe among the canes and often shelter in the dense, twiggy growth. Neither the green leaves nor the white flowers carry anything that would harm them.
People Safe
People, children included, take no harm from mock orange. It is not grown to be eaten, but a stray taste of leaf or white petal causes no real trouble.
No special handling required; as with any plant, discourage pets and children from chewing foliage to avoid mild stomach upset.
Varieties
Beyond the plain species, a few named selections stand out for the color of their leaves or the fullness and fragrance of their white bloom.
'Aureus'
'Aureus' pushes out new leaves in a bright golden-yellow that cools toward green as the summer heat builds.
'Variegatus'
'Variegatus' rims each green leaf with a clean, creamy-white edge that brightens the foliage in a shaded spot.
'Nanus'
'Nanus' is a compact dwarf whose low, dense frame stays well beneath the towering canes of the species.
'Minnesota Snowflake'
'Minnesota Snowflake' packs its cold-hardy canes with double white blooms, each flower full-petaled and heavily scented.
How to propagate
Mock orange multiplies readily, and three simple methods work with the shrub's own habit of rooting and suckering, chosen by season and effort.
Stem cuttingsEasy
Softwood cuttings in late spring to early summer; hardwood cuttings from dormant stems in late fall to winter · 4 to 8 weeks for softwood cuttings to root
Cuttings are the simplest way to raise more of this shrub. Soft green softwood cuttings come off in late spring to early summer, and firm, dormant hardwood cuttings in late fall to winter, with the softwood pieces striking roots in 4 to 8 weeks.
DivisionEasy
Early spring or fall · One growing season
The base of the plant throws up suckers, slim rooted shoots that dig and separate cleanly in early spring or fall. Each one knits into a full plant over a single growing season.
LayeringEasy
Spring to summer · One growing season or more
Layering works with the low, arching canes. A branch pinned against the soil any time from spring through summer roots where the bark meets the ground over a season or more.
Myths
Every shrub called mock orange is the same plant.
Several unrelated plants carry the name, and their flowers give them away. The true mock orange, Philadelphus coronarius, is a deciduous hydrangea-family shrub with four-petaled white flowers, while Pittosporum tobira is an evergreen with clustered five-petaled blooms and Murraya paniculata is a tropical evergreen that sets red fruit. They belong to entirely different genera and share only that orange-blossom scent.