Amaryllis (Knight's star lily) care

Light

In the wild amaryllis grows on the bright edge of a forest canopy, not in the canopy and not in the open. Indoors, that translates to within a metre of an unobstructed window, sheer curtain optional. Bright light with some direct sun during active growth drives reliable reblooming; a sunny window is ideal. Once buds open, move out of strong direct sun and away from heat to make flowers last longer. The fastest test: a hand held at the leaf casts a soft-edged shadow at noon — sharp shadow means too much sun, no shadow means too little light.

Watering

Aim for sparingly until growth appears, then keep evenly moist for amaryllis, but treat that as a starting point rather than a rule. A south-facing summer windowsill will dry the pot twice as fast as a north-facing winter room. Lift the pot; if it feels noticeably lighter than it did wet, water it. After potting, water lightly to keep the mix barely moist until the flower stalk reaches a few inches. Then water when the top 2 inches of soil dry out. Let pots drain freely and never leave the bulb sitting in water, which causes rot.

Soil and pot

Amaryllis grows best in rich, free-draining potting mix. Use a fresh, sterile potting mix high in organic matter (such as peat-based blends) in a pot with drainage holes. Choose a container only slightly wider than the bulb and plant with the top third to half of the bulb above the soil line. A pot with a working drainage hole is non-negotiable for this species — even free-draining mix will turn soggy in a closed planter. If you love the look of a decorative pot without a hole, use it as a cachepot around an inner nursery pot you can lift out to water.

Humidity and temperature

Amaryllis sits happiest at around Average household humidity (around 40-50%) humidity and 15-24C (active growth); 10-13C for dormancy (60-75F (active growth); 50-55F for dormancy). Amaryllis is not fussy about humidity and grows well in normal indoor air. No misting or humidifier is needed; good airflow actually helps prevent fungal issues like red blotch on stalks and leaves. If you keep the room above 15 year-round and avoid placing the plant near a cold draught, a hot radiator, or an air-conditioning vent, you have already handled the two biggest indoor stressors.

Fertilising

Feed amaryllis sparingly. Feed once new growth is visible, using a balanced or higher-phosphorus houseplant fertiliser at half strength roughly every two weeks (or each watering at quarter strength). Continue feeding the strap-like leaves after flowering to recharge the bulb for next season, then stop before the dormant rest. Skip fertiliser entirely on a stressed, recently-repotted, or actively wilting plant — fertiliser salts make damage worse, not better. Wait for a round of healthy new growth before resuming a feeding rhythm.

Common problems

Below are the issues we see most often on amaryllis in the Growli community. Each is annotated with the most common cause so you know where to start.

• Tall stalk but no leaves or flowers — Bulb may be undersized, exhausted, or stored too warm. Give bright light and consistent feeding after blooming so the bulb can recharge, and provide a proper cool dormancy before forcing again.
• Floppy or leaning flower stalks — Heavy blooms and low light cause stalks to flop. Rotate the pot for even light, stake tall stalks, and keep plants in bright conditions rather than dim corners.
• Bulb or root rot — Overwatering and poor drainage rot the bulb, often with a soft or mushy base. Water sparingly until growth starts, use a free-draining mix, and never leave the pot in standing water.
• Red blotch / red spots on stalks and leaves — A fungal disease (red blotch, Stagonospora) shows as red streaks or cankers and distorted growth. Improve airflow, avoid wetting foliage, and discard badly infected bulbs.
• No reflowering in later years — Without enough light, feeding, and a true dormant rest, the bulb won't bank energy to rebloom. Keep leaves growing in strong light after flowering, then rest the bulb cool and dry for 8-10 weeks.

Propagation

Easiest from offset bulbs ("daughter" bulblets) that form at the base of a mature bulb; separate them when repotting and pot up individually, though they take a few years to reach blooming size. Amaryllis can also be grown from seed, but seedlings are slow and won't match the parent hybrid. Propagation is the cheapest, most satisfying way to expand a collection — and it doubles as insurance against losing a mature plant to an accident. Take a backup cutting once the parent is established and healthy.

Toxicity to pets

Amaryllis is toxic to pets. The ASPCA lists Amaryllis (family Amaryllidaceae) as toxic to cats, dogs, and horses, with lycorine and related alkaloids the toxic principles; the bulb is the most concentrated part. Reported signs include vomiting, drooling, diarrhoea, abdominal pain, lethargy, and tremors. Keep bulbs and plants out of reach and contact a vet if ingestion is suspected. If you keep cats, dogs, or curious children in the house, weigh placement carefully — a high shelf or a hanging planter is enough for casual safety. For severe ingestion incidents, call your local vet and the ASPCA Animal Poison Control Center (in the US, 888-426-4435).

Pet-safety status is sourced from the ASPCA Toxic and Non-Toxic Plant List, which catalogues the most-asked-about plants for cats, dogs, and horses.

Amaryllis deep-dive guides

Every aspect of amaryllis care, each with its own calibrated guide:

• Amaryllis watering schedule
• Amaryllis light requirements
• Best soil mix for amaryllis
• Amaryllis fertilizing guide
• When to repot amaryllis
• How to propagate amaryllis
• Amaryllis growth rate & size
• Amaryllis cold hardiness
• Amaryllis temperature & humidity
• Is amaryllis toxic to cats & dogs?
• Getting amaryllis to bloom

Related guides

Amaryllis is also known as Amaryllis, Dutch amaryllis, Knight's star lily, Barbados lily, and Fire lily.

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• All 609 plant care guides in the Growli library