The vibrant and stunning blooms of amaryllis plants are a sight to behold. These popular bulbs produce showy flowers in shades of red pink white, and orange that can brighten up any indoor space. However, most amaryllis growers focus solely on the beautiful flowers and pay little attention to the roots and stems that support them. In this article, we will take a deep dive into amaryllis plant anatomy and explore the structure and function of the roots and stems that are so vital for growth.
Before looking at the roots and stems, let’s do a quick review of amaryllis plants. Amaryllis belong to the Amaryllidaceae family and are native to South America. There are over 600 species of amaryllis, with Hippeastrum being the most popular indoor variety. Amaryllis bulbs are often sold for indoor forcing and grown as potted plants. They are prized for their trumpet-shaped flowers that bloom on tall, leafless stems. With proper care, amaryllis can rebloom year after year to provide stunning color during the winter months. Now let’s look below the surface at the anatomy supporting those beautiful blooms!
The Root Structure of Amaryllis Plants
The roots of amaryllis plants have a critical job – to absorb water and nutrients from the soil Understanding the root structure leads to better care and growth Amaryllis roots consist of two main types
Fibrous Roots
As the name suggests, fibrous roots are threadlike and hair-like in structure. These thin, wiry roots emerge from the bottom of the bulb and spread out into the soil. Their key role is to absorb moisture and minerals from the soil. The greater the network of fibrous roots, the more nutrients the plant can take in.
Fleshy Roots
The fleshy, thicker roots are known as storage or adventitious roots. They emerge from the sides and bottom of the bulb to anchor it firmly in place. These meaty roots also act as storage organs, stockpiling water and nutrients to help the plant survive periods of drought or dormancy.
The combination of fibrous and fleshy roots makes for an efficient system to sustain amaryllis growth. Careful watering and fertilizing ensures the roots stay healthy to nourish the plant.
The Function of Amaryllis Stems
If roots act as the source, stems serve as the transportation system in amaryllis plants. Connecting the roots, leaves and flowers, stems have an important role in plant structure and function. The key functions of amaryllis stems include:
Support
The thick, erect stems provide structural support to the leaves, buds and flowers. As the flower stalks grow tall, the sturdy stems hold the blooms upright for maximum display. Their strength prevents drooping, especially of the heavy flowers.
Nutrient Transport
Stems act as the main conduit in the plant’s vascular system. They facilitate bidirectional movement of water, minerals and food nutrients between the roots and other plant parts. This transportation enables growth and development.
Phototropism
Stems exhibit phototropism or growth towards light by bending in the direction of sunlight. This helps optimize light exposure to promote photosynthesis in the leaves and developmental signals in the flowers.
Geotropism
Amaryllis stems show negative geotropism or growth against gravity. This characteristic makes the stems grow in an upward direction despite the pull of gravity. It results in vertical stem elongation that lifts leaves and flowers higher.
Caring for Amaryllis Roots and Stems
Now that we understand the internal workings of amaryllis roots and stems, let’s look at some care tips to keep them healthy.
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Allow time between waterings for the soil to dry out. Too much moisture will rot the roots.
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Use well-draining soil with added perlite or sand to prevent overwatering.
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Fertilize regularly during growth periods to provide nutrients for root and stem development.
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Support tall stems with garden stakes if needed to prevent breakage or drooping.
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Give young plants a grow light if natural light is inadequate for robust stem growth.
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Repot in fresh soil annually to provide roots with nutrients and room to spread out.
With the right growing conditions and care, the roots and stems will flourish to promote flowering year after year. Avoid overwatering, maintain even moisture, and provide bright light for the healthiest amaryllis plants.
The Takeaway
We mostly notice and appreciate the eye-catching flowers of amaryllis plants. However, those colorful blooms depend on the hidden work of roots and stems to thrive. Once you understand the anatomy and essential functions of these underground and supporting structures, you can better care for your amaryllis. By watering appropriately, giving light, providing nutrients, and allowing adequate space, the roots and stems will power spectacular, long-lasting flowers year after year.
Forcing Amaryllis in Water
Amaryllis can be grown in water in a vase, bulb-forcing jar, hurricane, or other clear container. The vase must be clear to monitor the water level as the plant grows. After flowering in water, these bulbs can be disposed of or potted in soil. They will not bloom again in water.
One method of growing Amaryllis in water is to use a bulb vase or forcing jar. These vases are transparent glass with a wide top for the bulb and a narrow neck or midsection that holds the bulb higher than the water in the bottom of the vase.
Add water to the bulb vase until it reaches one inch below the midsection of the vase. Place the bulb in the wide top, directing any roots down toward the water. As the amaryllis grows, it becomes top-heavy. To counterbalance the weight of the top growth, pebbles, marbles, etc., may be added to the vase for stability. Be sure to rotate the vase regularly so the stem will grow straight. Monitor the water level and refill as needed.
Another method of growing amaryllis in water is to use a large clear glass container, like a hurricane vase, with rocks so that the bulb is above the water level. Place pebbles, flat marbles, river rocks, shells, tumbled stones, or other vase fillers in the bottom of the container to a depth of 3 inches. Place the bulb on top of those pebbles, and then add more pebbles to the sides of the bulb. Leave the top 1/3 of the bulb visible. Add water to 1 inch below the bulb. Refill the water as needed.
Amaryllis bulbs dipped in colorful wax are available online, in catalogs, and in retail stores during the holiday season. These bulbs do not require water or soil because they contain enough stored energy to flower for the season. They do need light and warmth to bloom. Expect two flowering stalks per bulb. As the flower stalk grows, rotate the bulb daily to help the stalks grow straight.
Often, the wax is poured so that the bottom of the amaryllis bulb sits flat, ensuring it stands upright. A coiled wire may also be in the bottom of the bulb to hold it upright.
Waxed amaryllis are intended to be discarded after blooming.
For more information on bulbs, see HGIC 1556 Forcing Bulbs Indoors.
Amaryllis makes an excellent landscape plant and is cold hardy in South Carolina through USDA planting Zone 8. Amaryllis grown indoors during the holiday season can be moved outdoors in the spring after the threat of frost has passed. Gradually acclimate the indoor plants to brighter light by moving them to a porch or patio area before planting them in the garden.
Amaryllis grow well in good garden soil if the site is well-drained. An elevated planting bed may be necessary to ensure good drainage. A soil rich in organic matter will provide the best growth. Plant bulbs directly into the ground, spaced about a foot apart. Plant the bulb with only half its nose above ground, leaving the tops barely covered with soil.
Select a sunny spot in the garden that receives shade during the afternoon. Avoid placing the bulb where it will dry out excessively. Apply mulch, especially during the fall and winter months.
Fertilization determines the size and quality of the flowers and foliage. For garden plantings, use fertilizers containing low nitrogen, such as 5-10-10 or 6-12-12 analysis. Apply 1 to 1½ pounds per 100 square feet or 100 feet of row to be established. A bulb booster-type fertilizer can also be used. Make the first fertilizer application as new growth begins, then repeat the application when the flower stalk is 6 to 8 inches tall. Apply a third application immediately after flowering when the old flower heads and stems have been removed.
Amaryllis grown outdoors are deer resistant.
The main disease problems of amaryllis are mosaic virus, bulb rots, and “red blotch.” Plants infected with mosaic virus have a light-yellow streaking of the leaves and reduced growth and flowering over the years. There is nothing one can do to eliminate the mosaic virus from an infected plant.
Bulb and root rot problems typically occur when the soil is kept too wet or when bruised bulbs are planted. When bulb or root rot problems are suspected, discard diseased bulbs and replace the potting soil.
The fungal disease “red blotch” or “leaf scorch” causes reddish brown spots on the bulb, leaves, and/or scape (flower stalk). It can spread rapidly within a bulb and from bulb to bulb.
Insects and other pests that can become a problem include scale, mites, thrips, bulb maggots, and mealybugs. For more information on controlling insect pests, see HGIC 2770, Less Toxic Insecticides.
All parts of the amaryllis are poisonous to humans and pets if ingested in large quantities. The bulb is the most toxic part of the plant. Originally published 06/99
If this document didn’t answer your questions, please contact HGIC at [email protected] or 1-888-656-9988.
Nancy Doubrava, Former HGIC Horticulture Information Specialist, Clemson UniversityRobert F. Polomski, PhD, Associate Extension Specialist—Environmental Horticulture/Arboriculture, Clemson University
Ginger Elizabeth Long, HGIC Agent, Home & Garden Info Center, Clemson Extension, Clemson University
This information is supplied with the understanding that no discrimination is intended and no endorsement of brand names or registered trademarks by the Clemson University Cooperative Extension Service is implied, nor is any discrimination intended by the exclusion of products or manufacturers not named. All recommendations are for South Carolina conditions and may not apply to other areas. Use pesticides only according to the directions on the label. All recommendations for pesticide use are for South Carolina only and were legal at the time of publication, but the status of registration and use patterns are subject to change by action of state and federal regulatory agencies. Follow all directions, precautions and restrictions that are listed.
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Plant Anatomy and Morphology
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