Amaryllis bulbs produce large, bell-shaped flowers, and they flower year after year if you plant and care for them properly. These bulbs grow well both indoors and in warm conditions outdoors, and different varieties of bulbs flower in bright colors including red, white, orange and yellow. Amaryllis bulbs are hardy and relatively easy to grow, but, like all living things, they may fall victim to problems caused by moisture, physical damage, viruses, bacteria and insects.
Moisture and Physical Damage
Excess water and physical damage cause amaryllis bulbs to rot. If you have already planted the bulbs, their roots may rot if you give them too much water. Make sure not to plant bulbs that are bruised or that have been stored in a damp place. Remove any damaged bulbs that you have already planted, and replace the soil surrounding them with fresh, clean topsoil.
Different varieties of mosaic virus, such as tobacco mosaic virus and cucumber mosaic virus, can attack amaryllis bulbs. It reduces flowering and stunts growth, and you can spot it by its telltale yellow leaf streaks in a mosaic-like pattern. This disease cannot be treated, and it can spread to healthy plants even when the responsible pathogen is only found in a single bulb. Prevention consists of removing affected plants, replacing affected soil, and sterilizing any implements used to remove or dispose of such plants with a solution of bleach and water.
Infection with the fungus Stagonospora curtissi causes red blotches to appear on the stems and leaves of growing amaryllis plants, giving this disease the name red blotch. The blotches begin forming on infected bulbs, but they can mimic similar, harmless bulb blotches. Inspecting bulbs carefully and planting only those with blotches that do not go beyond the skin of the bulb prevents red blotch from appearing. Fortunately, red blotch is usually not fatal to growing plants. You can apply a systemic fungicide such as thiophanate-methyl to affected plants, and soaking bulbs in a solution of this type of fungicide helps to prevent red blotch.
Insect and Animal Pests
The narcissus bulb fly attacks and lays eggs in amaryllis bulbs. Destroy any bulbs that are infested with maggots or show signs of rot when pressed. Prevent infestations by storing dormant bulbs indoors, especially during the summer, and by destroying any plant with wilted or otherwise misshapen leaves. Bulb mites and mealybugs can also infest amaryllis bulbs, and you should dispose of any bulb with any sign of insect presence. Hot water dips can stop nematodes, which are small, destructive roundworms, from multiplying in amaryllis bulbs. Rabbits, squirrels and pocket gophers often eat amaryllis bulbs. Repellents, traps and poisons are available to control these animals, but trapping and poisoning are best left to professionals.
Your Planting Articles
- Clemson Cooperative Extension: Amaryllis
- Florida State Horticultural Society: A Mosaic Disease of Hybrid Amaryllis..
- University of California Cooperative Extension: Central Coast & South Region: Understanding and Producing Amaryllis
- UC-IPM Online: Floriculture and Ornamental Nurseries: Nematodes
- University of Minnesota: Growing and Caring for Amaryllis
- Cleary Chemical Corp.: 3336 WP: Specimen Label
- Clemson Extension: Horticulture: Understanding and Producing Amaryllis
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