Anthurium care: light, water and humidity for steady blooms

Light

Light controls flowering. NC State recommends bright, indirect sunlight and notes that too little light means fewer blooms and slower growth, while direct sun scorches the leaves. Its genus profile names south- and west-facing windows as best, with the plant set back or screened so sun never strikes the foliage. The University of Illinois Extension lists anthurium in its medium-light group, about 150 foot-candles, and UF/IFAS Gardening Solutions stresses that, unlike garden plantings in Florida shade, an indoor anthurium needs bright indirect light to thrive.

UF/IFAS research is encouraging for darker homes: several potted cultivars flowered continuously for more than a year and a half under interior light of 100 foot-candles. Too much light, on the other hand, bleaches leaf centers and browns the tips, and Florida growers keep their crops under heavy shade for that reason. If an anthurium produces healthy leaves but no new spathes, light is the first thing to raise.

Water

NC State's rule is to water when the top inch of the mix feels dry. UF/IFAS describes the same pattern for indoor plants: allow the mix to dry slightly, then water thoroughly so the excess runs out of the pot. Because the roots evolved in airy debris on tree branches, they rot quickly in a dense, constantly wet container, and NC State lists overwatering as the cause of both root rot and yellowing leaves.

Water quality matters more than for most foliage plants. NC State recommends rainwater or purified water, and UF/IFAS warns that accumulated salts cause marginal and tip burn. Keep water off the foliage where you can: leaf spots, NC State says, follow wet leaves and poor air circulation. In winter, growth slows with shorter days and the mix stays damp longer, so feel it before every watering rather than keeping a summer rhythm.

Soil and pH

Use an open, epiphytic mix. UF/IFAS growers pot anthuriums in equal parts peat, perlite and bark, at pH 6.0 to 6.5, and note that the plants root best in well-aerated media. A home version combines orchid bark, a peat-free or coir-based houseplant mix and perlite in roughly equal parts. Avoid fine, dense potting soil, which collapses around the thick roots and stays wet. Aerial roots that appear on the stem above the surface are normal for an epiphyte; guide them into the mix or leave them alone.

Humidity

NC State gives an ideal of 60 to 80 percent relative humidity, and UF/IFAS warns that below 50 percent the leaves lose their gloss and may die back. Brown leaf tips are the usual sign of dry air, according to NC State. For indoor plants, UF/IFAS suggests standing the pot on a tray of moist gravel, and NC State notes that many growers keep anthuriums in terraria or growing cabinets. Through winter heating, a humidifier in the same room is the most dependable fix.

Temperature

NC State gives 65 to 80°F (18 to 27°C) as the preferred range for the flamingo flower, and its genus profile extends that to 85°F. UF/IFAS recommends interior temperatures between 70 and 85°F and keeping the air above 55°F (13°C), below which visible or hidden damage can occur and growth stalls even after warmth returns. Anthuriums do not tolerate cold drafts or sudden swings, so keep them away from doors and air-conditioning vents, and from appliances that give off heat, a hazard UF/IFAS specifically mentions.

Fertilizer

The sources differ on frequency. NC State recommends liquid fertilizer weekly during the growing season, while UF/IFAS interior guidelines call for a 20-20-20 water-soluble fertilizer at about 50 ppm nitrogen once a month. Either approach works as long as each dose is weak, because UF/IFAS warns that overfeeding indoors builds salts that burn leaf margins and tips. The NC State genus profile adds that a high-phosphorus fertilizer encourages more blooms, and commercial growers switch to a formula with relatively more phosphorus and potassium to promote flowering. Feed less in winter, when the plant rests.

Work out the dose for your watering can with the fertilizer dilution calculator →

Repotting

NC State recommends repotting every two to three years, or whenever the plant appears root-bound, in spring. Signs include roots circling the pot or pushing through the drainage holes, and a bark mix that has broken down into fine, soggy material. Anthuriums develop short stems as they age, so the crown can gradually rise above the surface. Replant at the same depth, as the University of Illinois Extension advises, and tuck any aerial roots into the fresh mix.

• Roots circle the pot or grow out of the drainage holes
• The bark mix has broken down and stays soggy
• The crown and aerial roots rise above the surface of the mix

Propagation

NC State lists division and stem cuttings. Mature plants often form several crowns; in spring, unpot the plant and pry or cut them apart so each piece keeps a fair share of roots, the method the University of Illinois Extension describes for clumping plants, then repot immediately so the roots do not dry. A stem that has grown tall with aerial roots can be cut below those roots and potted as a new plant. Seed is possible but slow, and UF/IFAS notes that almost all commercial anthuriums are now produced by tissue culture.

Methods: Division of multi-crowned plants, Stem cuttings with aerial roots · Best season: spring.

Common problems

Few or no flowers point to too little light or a lack of nutrients, NC State says, and yellow leaves follow overwatering, poor drainage or a nutrient shortage. Watch for aphids, spider mites, mealybugs, scale and thrips. UF/IFAS adds that bleached leaf centers with brown tips mean too much light, and broad, dry, tan blotches are a sign the light is far too strong. Cut off faded spathes at the base of their stalk to keep new ones coming.

Not sure which one it is? Try the plant problem diagnosis tool →

Is the anthurium toxic to cats and dogs?

The ASPCA's flamingo flower entry is filed under Anthurium scherzeranum, the smaller pigtail anthurium with a curled spadix, rather than under A. andraeanum, the species most often sold. The ASPCA rates it toxic to dogs, cats and horses, with insoluble calcium oxalates as the toxic principle and clinical signs of oral irritation, pain and swelling of the mouth, tongue and lips, excessive drooling, vomiting (not horses) and difficulty swallowing. NC State describes the same calcium oxalate crystals and similar symptoms for A. andraeanum and for the whole genus, rating the severity as low for people, with stinging skin or eyes from the sap. Treat every anthurium as toxic, keep it out of reach, and call your veterinarian or the ASPCA Animal Poison Control Center at (888) 426-4435 if a pet chews one.

Check any other plant against the ASPCA lists →