Shrub · Ericaceae
Encore Azalea
Rhododendron
Rooted in acidic soil, filtered sun, and steady moisture, the Encore azalea opens flowers in spring and again into fall.
Partial sun
Every 3–7 days
USDA 6–10
2–5 ft · 0.6–1.5 m
Overview
Up close, the Encore azalea is a reblooming shrub clothed in small, leathery evergreen leaves that hold their green through the year. The first flowers open in spring, the way any azalea does, and then a fresh crop unfurls again from summer into fall, scattering color over the foliage. It sits in the genus Rhododendron, in the heath family, a hybrid series carried by waves of bloom rather than a single spring burst.
Watch how it answers the light. Older garden azaleas languish in anything brighter than dappled shade, yet the Encore drinks in more direct sun and turns it into the second and third flush of flowers that stud its branches. Where the light thins out, those repeat blooms grow scarce and the shrub leans on its evergreen leaves alone.
Beneath the show, this is a plant of acidic, well-drained soil and steady moisture drawn up through shallow roots, and it asks little once settled. The branches need only light pruning, the spent flowers drop without help, and the whole shrub rounds into a dense, leafy mound over the years. Look but do not taste, though, since every part of it holds toxins dangerous to pets, livestock, and people.
Care
The short version: set its shallow roots into acidic, well-drained soil under filtered sun with afternoon shade, keep them evenly moist but never waterlogged, feed the shrub an acid-forming azalea fertilizer in late spring, and prune the branches lightly just after the spring bloom.
Light
The Encore azalea holds its color best in filtered or partial sun, and unlike old garden types it stands up to some full sun on its leaves. Bright light with a little afternoon shade suits the foliage. In deep shade the repeat flowers thin out, while harsh, hot sun scorches the leaves, stresses the shrub, and draws lace bugs to the undersides.
Water
Keep the soil evenly moist but well-drained around the shallow roots, soaking it deeply to 6 to 8 inches once the top few inches dry. A young plant in sandy soil may want a drink about twice a week through its first year. Steady moisture keeps the leaves firm and glossy, while standing water turns the fine roots dark and soft.
Soil
These shrubs sink their roots into acidic soil, ideally a pH of 4.5 to 6.0, that drains freely and stays rich with organic matter. Pine bark or compost worked into the bed feeds that fibrous root mass, and the crown sits a touch high. Heavy, soggy ground packs around the roots and is the quickest way to kill one.
Temperature
The Encore azalea carries its evergreen leaves across a wide band of cold and heat, from about -9°F to 100°F (-23°C to 38°C), which covers zones 6 through 10. The shrub takes deep winter chill and summer heat alike. In the coldest zones, drying wind can desiccate the leaves of young plants, so a little shelter helps.
Humidity
Ordinary outdoor air around the foliage suits them, so there is no number to chase. Air circulation through the branches matters more than moisture in the air, since a still, crowded, damp canopy holds wetness on the leaves and flowers and invites petal blight and lace bugs.
Feeding
Feed the shrub a complete, slow-release acid-forming azalea fertilizer, around a 2-1-1 ratio, in late spring once the new growth flushes and on into early summer. Skip late-fall feeding, which pushes out soft, tender shoots just before the cold. One seasonal feeding keeps the leaves a healthy green.
Pruning
The branches need very little pruning to keep their rounded shape. To shape or thin the shrub, cut just after the spring flush so the wood that carries the rebloom stays on the plant. The faded flowers drop on their own, so deadheading is unnecessary.
Repotting
Encore azaleas rarely need repotting and root best out in open ground. In a container, roots circling the soil ball and growth that stalls show the fibrous root mass has filled the pot and needs a larger one with fresh acidic mix.
Size & spacing
A mature shrub stands 2 to 5 feet (61 to 152 cm) tall and spreads wider than it is high, around 3 to 4 feet (91 to 122 cm) across, building a broad, leafy mound. Give each plant room for that full spread so air moves between the branches and the leaves dry after rain.
When to plant
The Encore azalea grows as a woody, evergreen shrub hardy in zones 6 through 10, planted from nursery stock rather than raised from seed. Its roots take best to the ground in spring or fall, while the weather is mild and the soil stays workable. The branches open their first flowers in spring, and the reblooming habit sends out more color from summer through 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: Spring, then again summer through fall
Hardiness
USDA hardiness zones: 6–10
Temperature: down to -23°C
Troubleshooting
Most of what goes wrong with an Encore azalea writes itself across the plant in plain sight, on the leaves, the flowers, or the roots below. Too much sun draws lace bugs to the foliage, and too much water rots the roots, so reading those parts closely catches the trouble early. Match the signs you see below, then act before they spread through the shrub.
Drooping shoots above blackened, rot-softened roots
When the leaves wilt and whole branches die back even with water in the soil, the trouble is underground, likely Phytophthora root and crown rot in wet, poorly drained ground. Scrape the soil from the base and the roots show dark and mushy rather than firm and pale. A badly rotted plant cannot recover, so lift it out, fix the drainage, and set a replacement shallow in acidic soil amended with pine bark.
Fix:
- Improve drainage and avoid overwatering
- Remove severely affected plants
Silvery-stippled leaf tops with dark flecks beneath
Leaves that fade to a grayish, whitish, finely speckled surface are showing azalea lace bug damage, the color drained from above as the insects feed below. Turn a leaf over and the underside reveals lacy-winged adults, spiny nymphs, and dark, varnish-like specks of waste, or wipe it on white paper to rule out spider mites and their red streaks. Coat the undersides with a labeled insecticide, or use a soil systemic for season-long cover, and shift the plant out of hot full sun where the stippling spreads fastest.
Fix:
- Treat undersides of leaves with a labeled insecticide such as acephate, bifenthrin, malathion, or cyfluthrin
- For season-long control use a soil-applied systemic such as imidacloprid or dinotefuran
- Plant lace-bug-resistant cultivars where possible
Spot-marked petals melting to a slick pulp
Petals freckled with small spots, pale on colored flowers or rust-toned on white ones, that swell into blotches and slump into a slimy mass are in the grip of petal blight, a fungus of cool, wet weather. The marks enlarge across the bloom until it collapses within days. Pick off and bin the spotted flowers, water at the base so the petals stay dry, and open the branches so air moves through the canopy during bloom.
Fix:
- Remove and dispose of infected blooms
- Improve air circulation and avoid overhead watering during bloom
Toxicity
For all the beauty in its leaves and flowers, this plant is genuinely dangerous to eat. Every part of an Encore azalea, leaf, stem, and bloom alike, holds grayanotoxins, the same compounds found across the rhododendrons, and even a few leaves or flowers can sicken a pet. Keep the shrub, its prunings, and any fallen leaves and flowers well away from cats, dogs, horses, livestock, and curious kids.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds · People
Cats Severe
Even a couple of the leaves can make a cat very sick. The early signs are drooling, vomiting, and diarrhea, then weakness and an unsteady, wobbly walk. In larger doses the grayanotoxins disturb the heart rhythm and drop the blood pressure, and a cat can collapse, so treat any nibble of leaf or flower as an emergency.
Dogs Severe
A dog that chews the leaves or flowers usually drools, vomits, and develops diarrhea within hours. Tremors, weakness, and loss of coordination can follow as the toxin spreads. A big mouthful of foliage threatens the heart and blood pressure, which is why even a small amount warrants a fast call to the vet.
Horses Severe
Horses cannot vomit, so the grayanotoxins from the leaves hit hard and stay in. Expect colic, diarrhea, drooling, and deep weakness, and in serious cases the heart begins to fail. Browsing horses are at real risk, so keep clippings and fallen leaves well out of reach.
Rabbits Severe
The same grayanotoxins that poison cats and dogs are dangerous to rabbits. A nibble of leaf or flower can bring on a sluggish gut, loss of appetite, weakness, and a slowed heartbeat. Never offer azalea leaves or flowers, and clear any prunings from where a rabbit grazes.
Livestock Severe
Goats, sheep, and cattle are poisoned by even small amounts of azalea foliage, and grazing animals sometimes eat enough to die. Drooling, repeated vomiting or regurgitation, staggering, and a faltering heartbeat are the usual signs. Fence the shrubs off and never toss trimmings into a pasture.
Birds Severe
The grayanotoxins packed into leaf, stem, and flower are hard on birds, whose slight bodies leave almost no margin. A bird that nips a glossy leaf or a petal can go limp, sway off its perch, and slip into an uneven heartbeat. Keep any pet bird well away from the plant's foliage.
People Caution
No part of an azalea, leaf or flower, is meant to be eaten, and the grayanotoxins can sicken a person too. A child or adult who swallows them may feel nauseated and weak, with vomiting and, in larger amounts, a slowed or irregular heartbeat. Keep the plant out of reach of small children and call poison control if anyone eats it.
Keep plants, prunings, and fallen leaves and flowers away from pets and livestock; even a few leaves or flowers can cause serious signs.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
Poison Control: (800) 222-1222
Canada
Poison Centres: 1-844-764-7669
Varieties
The Encore series runs to many named cultivars, told apart mostly by the color of their blooms. These four trace the range across the petals.
Autumn Royalty
Autumn Royalty is a reblooming Encore cultivar whose petals open a rich, deep purple.
Autumn Twist
Autumn Twist is a reblooming Encore type whose blooms wear striped, bicolor markings.
Autumn Fire
Autumn Fire is a reblooming Encore cultivar whose flowers glow a bold, saturated red.
Autumn Moonlight
Autumn Moonlight is a reblooming Encore type whose petals open a clean, pure white.
Companions
Encore azaleas do best under high, open trees that filter the light and drop an acidic mulch as their leaves break down.
Plant near
Oak: Provides high filtered shade while allowing enough light, and its leaf mulch breaks down to acidify and feed the soil
Pine: Gives filtered shade and acidic needle mulch suited to azaleas' soil needs
How to propagate
More of these leafy shrubs come straight from the plant itself, either by rooting a cut piece of stem or by layering a low branch down into the soil, with patience the price of both.
Stem cuttingsModerate
Late spring to summer from semi-hardwood growth · Several weeks to months to root
Cut a piece of current-season, semi-hardwood stem from late spring into summer, when the wood has begun to firm, and press it into a moist, well-drained acidic medium. The cut stem roots slowly, often over several weeks to a few months, so keep it humid and wait until new leaves push out to show it has taken.
LayeringEasy
Spring · One or more growing seasons
Layering works the low branches into new plants. In spring, bend a low, flexible stem down, pin it into acidic soil, and leave it joined to the parent while roots form along the buried wood, which can take a full growing season or more. Once the new roots hold, cut the stem free and lift the rooted piece to its spot.
Myths
Azaleas are just faintly poisonous, so a nibbled leaf won't harm a pet.
The grayanotoxins run through every part of the plant, leaf, stem, and flower, and the dose in just a few leaves is enough to do real harm. A small nibble can trigger vomiting, weakness, and a dangerous heart rhythm in a cat or dog, and a larger one can kill. Treat any azalea this seriously, and keep pets away from the whole plant.
Encore azaleas need deep shade, the way old-fashioned azaleas always did.
These were bred to hold more sun on their leaves than traditional azaleas. To set the repeat flowers they want at least 4 to 6 hours of sun, ideally with some afternoon shade, so deep shade leaves the branches carrying few of the blooms they are grown for.