Amaryllis

About Amaryllis

The amaryllis sold as a gift bulb each winter is a Hippeastrum hybrid from Central and South America, not the South African Amaryllis genus the name belongs to (NC State). A big bulb potted in November sends up one to three hollow stalks topped with 2-6 trumpet flowers up to 5-8 in across, in red, pink, orange, salmon, white and stripes, about 4-8 weeks later (Clemson, NC State). With a summer outdoors and a cool dry rest in fall it reblooms year after year, and the bulb is the poisonous part.

Hardy outdoors in zones 7-10 with winter mulch, and in zone 8 in South Carolina (NC State, Clemson); north of that it is grown indoors and can summer outdoors in part sun once nights stay above about 50 F, coming back in by mid-September (Iowa State).

When to plant

Timing is counted from your average last spring frost (and first fall frost). Sow & Tell works out the actual dates for your ZIP code.

Bought as a dormant bulb and potted between mid-fall and late winter, early to mid-November for Christmas bloom; bloom comes 4-8 weeks after potting (Clemson, Iowa State, NC State).

Growing it indoors

• Light: Give it at least 4 hours of direct sun a day in a south window (east or west second best) and turn the pot every few days so the stalk grows straight; move it out of direct sun only while the flowers are open, to make them last (Clemson, Iowa State).
• Water: Water thoroughly after potting, then wait about a week and keep the mix just barely moist until growth shows; once leaves and stalk are up, water when the surface feels dry, about once or twice a week in bloom, and never leave the pot standing in water (Clemson, Iowa State). After bloom keep it slightly moist through summer, then stop watering in fall for the 8-10 week rest.
• Temperature: Start the bulb at 70-75 F, drop to 65-70 F in bloom to make the flowers last, rest it at 50-55 F in fall, and keep it away from heaters and vents; the plant is injured below 35 F (Clemson, Iowa State, NC State).
• Feeding: Never feed a leafless bulb; once it is growing, feed every 2-4 weeks with a balanced liquid houseplant fertilizer at half strength through spring and summer, and once or twice a month outdoors through July, then stop in fall (Clemson, Iowa State).
• Repotting: Bulbs flower best slightly rootbound, so repot only every few years, at the end of the fall rest, into a pot 1-2 in wider than the bulb with fresh mix and the top half of the bulb above the surface (Clemson, Iowa State).

Soil

A well-drained potting mix, or equal parts peat and perlite, in a heavy pot with a drainage hole only 1-2 in wider than the bulb, with the top third to half of the bulb above the mix (Clemson, Iowa State).

Pot in a well-drained potting mix or equal parts peat and perlite, in a pot 1-2 in wider than the bulb with a drainage hole, with the top third to half of the bulb above the mix (Clemson, Iowa State).

Feeding

• From potting until leaves show: none. Never fertilize a leafless bulb; it can kill the new roots (Clemson).
• Once leaves and stalk are growing, through bloom and spring: balanced liquid houseplant fertilizer. Feed every 2-4 weeks at half strength (Iowa State), or twice a month diluted per the label (Clemson), after watering.
• Summer outdoors, through July: balanced liquid houseplant fertilizer. Feed once or twice a month to build the bulb for next winter's flowers (Iowa State); in the ground Clemson uses a low-nitrogen 5-10-10 or 6-12-12 at new growth, when the stalk is 6-8 in, and after bloom.
• Fall rest, 8-10 weeks at 50-55 F: none. Stop watering and feeding when you put the bulb to rest in late September (Iowa State, Clemson).

Leaves but no flowers next year means the bulb didn't store enough food: feed more through spring and summer and don't skip the cool rest (Iowa State).

Harvest

Flowers open 4-8 weeks after potting, each stalk carrying 2-6 blooms that last 3-4 weeks; cut a spent stalk 1-2 in above the bulb and leave the leaves to feed next year's flowers (Clemson, Iowa State, NC State).

Varieties (19)

Pests to watch for

Mealybugs, Thrips, Scale insects, Twospotted spider mite, Narcissus bulb fly, Slugs, Brown garden snail

Diseases and problems

Red blotch (leaf scorch), Root and crown rot, Mosaic viruses

In the kitchen

Safety: The bulb is the most poisonous part: it contains the alkaloid lycorine, and NC State rates it medium severity, with vomiting, drooling and diarrhea after a mouthful and convulsions, low blood pressure, tremors and irregular heartbeat after a large one; leaves, stems and flowers carry less. Store spare bulbs where children can't mistake them for onions.

Pets: Toxic to dogs, cats and horses (ASPCA, listed as Amaryllis spp.): lycorine and other alkaloids cause vomiting (not in horses), depression, diarrhea, belly pain, drooling, loss of appetite and tremors, and the bulb is the worst part.