Arum
( AR - rum )
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At-A-Glance InformationCommonly called Arum Lilies, these perennial flowers grow from tubers in partial or full shade, and need regular waterings during growth and flowering periods. Leaves are arrow-shaped and attractively veined with white or cream. Stalks will produce a colored bract that encloses a spadix of tiny flowers that are sometimes fragrant. Blossoms are followed by dense fruit clusters that last even after the leaves of the plant have faded. Arum is great for shady border areas of the garden or as a tropical-type groundcover. Take care when planting these flowers in your garden, as physical contact can be irritating to skin and the plant is toxic if ingested.
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Arum Species and Varietals
The genus Arum includes around 30 species and is a member of the plant family Araceae. The genus name is derived from the Latinized Greek name for these plants, 'aron'. Although they are commonly called Arum Lilies, these plants are not closely related to the genus Lilium. Arum is more closely related to the genus Zantedeschia, a genus whose plants are also commonly called Arum Lilies. The best growing zones for Arum depend on the species; for more information, read the descriptions below. To find your zone, click here: Zone Map.
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Arum apulum (Apulian Arum, Apulian Lords and Ladies) This species is endemic to Italy, and is threatened by habitat loss in its natural range. It prefers to grow in low scrub landscapes and spreads clonally through its tuberous root system. Individual plants reach up to between 8 and 30 inches tall when in bloom, and produce leaves that can reach up to a foot in length. Best in USDA hardiness zones 7-10. |
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Arum besserianum (Besserianum Arum, Arum Besserianum Plant) This species of Arum Lily is native to southern Poland and northwestern Ukraine. The spathe is commonly light green to cream in color. Leaves are large and green, shaped like arrowheads. Flowers are followed by red berries. Grows to reach between 8 and 24 inches tall at maturity. This species does well in USDA zones 5 and 6. |
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Arum coccinatum (Crete Arum) This species of Arum Lily is found naturally in wet areas and olive groves in southwestern Turkey and the eastern Mediterranean islands. Foliage is green, and in springtime, a dense spadix is produced surrounded by a large, burgundy, green, and yellow spathe. It grows to reach up to 2-3 feet tall at maturity when in bloom. This species grows in USDA hardiness zones 5-9. |
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Arum creticum (Cretan Arum) This species is native to the Greek island Crete, southwestern Turkey, and the eastern Aegean Islands and is best when grown in USDA hardiness zones 7b-9b. It is semi-evergreen, and forms a clump of foliage. Flowers are fragrant and spathes are cream to white. Fruit is red to orange. This species of Arum Lily reaches about 20 inches tall when in bloom. |
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Arum cylindraceum (Mountain Arum, Lords and Ladies) This woodland species of Arum Lily produces leaves in early springtime, followed by flowers protected within a green spathe. Berries are bright red. Individual plants can reach up to between 6 and 16 inches tall when mature and in bloom. This species is native to most of Europe and grows well in USDA hardiness zones 5a-9b. |
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Arum dioscoridis (Spotted Arum) This species of Arum Lily is native to southern Turkey, Cypress, Greece, and the Middle East. It was first described by James Edward Smith in the publication Flora Graeca, and is named after the ancient Greek physician and botanist Pedanius Dioscorides. Leaves appear in wintertime, and flowers on a short stem appear in spring. The spathe is yellow-green, with dark red to maroon mottling in the throat. Plants reach 8-12 inches tall and are best when grown in USDA zones 5a-9b. |
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Arum hygrophilum (Streambank Arum, Water Arum) This species is found in Israel, Jordan, Lebanon, Syria, Cyprus, and Morocco and grows well in USDA zones 6a-9b. They do very well in damp or watery environments, such as along streams or wetlands. The spathe on these plants is cream to white, with a deep red to maroon lining. Plants reach up to 2 feet tall when mature and in bloom, and a dark maroon to purplish spadix surrounded by a pale green spathe with a maroon edge. |
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Arum italicum (Italian Arum, Italian Lords-and-Ladies, Cuckoo's Plant, Orange Candle Flower, Aaron's Rod) Grows best in USDA hardiness zones 5-9 or Sunset growing zones 2-24; this species is native to southern and western Europe. Leaves sprout in fall or early winter, and short stems hold white (sometimes greenish or with purple spots) bracts in spring and summer, followed by orange-red fruits. Leaves die to the ground after blooms fade, and plants will naturally multiply by volunteer seedlings. Variety 'Marmoratum' ('Pictum') has leaves with white veining. This species is considered invasive on the West Coast and Mid-Atlantic regions of the United States. |
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Arum maculatum (Adam and Eve, Adder's Meat, Adder's Root, Cuckoo Plant, Naked Boys, Snakeshead, Starch-Root, Wake-Robin) This species, native to Europe, Turkey, and the Caucasus, grows in woodland areas and along riversides. Varieties include Arum maculatum maculatum (with purple-spotted leaves) and Arum maculatum immaculatum (with green leaves). Berries that follow blooms are orange-red. Plants reach up to 12-18 inches tall at maturity when in bloom, and grow best in USDA hardiness zones 5-9. |
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Arum nigrum (Black Arum, Balkan Black Arum) This species produces a large underground tuber, from which it produces glossy green arrow-shaped leaves and flowers surrounded by a dark maroon to black spathe. These flowers are native to the Balkan Peninsula and northern Greece. Best in USDA hardiness zones 6a-8b. |
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Arum palaestinum (Black Calla, Solomon's Lily, Priest's Hood, Noo'ah Loof, Kardi, Wild Calla) This native of Israel grows best in USDA hardiness zones 7b-10b and Sunset growing zones 14-24. Leaves emerge in winter, and the spathe opens to reveal a purple interior and black spadix. Flowers bloom in spring and early summer, and then leaves die back to the ground. This species is best known for its long history of use as a food in the Middle East and for its use in traditional Middle Eastern medicine. |
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Arum pictum (Autumn Arum) This native of the Mediterranean grows best in USDA hardiness zones 5a-9a or Sunset growing zones 7-9 and 14-24. Spathe is violet with a white base and encloses a dark purple spadix. Flowers bloom in fall, and light green leaves have white veining. Foliage dies to the ground in hot weather. Plants reach up to between 10 and 18 inches tall when mature and in bloom. |
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Arum sintenisii (Sintenis Arum) This species is native to uncultivated Olive Tree groves in northern Cyprus and southwestern Turkey, and grows well in USDA hardiness zones 6a-10b. It is able to survive mild winters without dying back to the ground, and produces a purple spathe around a purple spadix at leaf height. These plants reach up to between 8 and 12 inches tall when mature and in bloom, with a width of between 6 and 12 inches. |
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Caring for Arum
Take care when planting these flowers in your garden, as physical contact can be irritating to skin and the plant is toxic if ingested. Arum plants are typically purchased either as tuber roots or as specimens from a reputable nursery. Arum tubers should be planted in well-draining soil in late summer or early fall, set 8-12 inches apart and 4-6 inches deep. The best spot in the landscape to plant Arum Lilies is in partial to full shade. these flowers can be planted in the ground, though many people choose to cultivate them in pots to easily move them indoors and outdoors when necessary, as the rhizome roots do not always survive deep frosts. Plant in a place in the landscape that receives partial shade, or in a greenhouse. They like to get reflected, indirect light or dappled light for most of the day, but can do well in a space that gets morning sun and afternoon shade, as well. These plants prefer to have their roots in fertile, moist soil that drains well and has a pH of between 6.0 and 7.5. If local soils are compacted, do not drain well, or are particularly poor in nutrients, make sure to amend the planting area with plenty of organic matter or compost before installing. Apply a thick layer of mulch around the base of the plant after installation, ensuring that mulch stays at least a few inches away from the stems. This will increase soil moisture retention, suppress weed growth, and maintain a constant soil temperature.
Water new plants regularly as they establish a strong root system in their new environment. Mature plants should be given water any time the top inch or two of soil feels dry to the touch. In climates with no frost, rhizomes can be left in the ground over the winter months. Mulching over the tops of plants during the coldest months of the year can help them to survive, as well. In areas with hard freezes, grow these plants in containers and move them indoors or to a more protected location over wintertime or dig them up each fall and replant them in springtime. Pruning is relatively straightforward for these plants; after they are done flowering and fruiting, cut back the flowering stem to the base of the plant. Any remaining foliage can be cut back in this way as well. New foliage and flowering stems will form and bloom in the next growing season. These plants will need to be divided every so often for ongoing health, especially when grown in containers. For instructions on how to successfully divide Arum lilies, see the Propagation section below. Arums are able to survive in the landscape for decades or longer provided with proper care, and will form clumps over time.
Caring for Arum in Containers
Although Arums grow very well in the ground, they also thrive in pots, which can allow for growers in cooler zones to grow these frost-sensitive flowers. Choose a pot that is a few inches wider and deeper than the original nursery pot or root ball. Choose a well-draining soil amended with plenty of organic material and perlite, and top with a dressing of mulch to increase soil moisture retention, suppress weed growth, and maintain a constant soil temperature. Water new plants regularly as they establish a strong root system in their new environment. Mature plants should be given water any time the top inch or two of soil feels dry to the touch. In cooler areas, move containers into protected areas during the winter months. Pruning is relatively straightforward for these plants; after they are done flowering and fruiting, cut back the flowering stem to the base of the plant. Any remaining foliage can be cut back in this way as well. New foliage and flowering stems will form and bloom in the next growing season. Repot when roots begin to grow through the drainage holes at the bottom of the container. These plants will need to be divided every so often for ongoing health, especially when grown in containers. For instructions on how to successfully divide Arum lilies, see the Propagation section below.
Water new plants regularly as they establish a strong root system in their new environment. Mature plants should be given water any time the top inch or two of soil feels dry to the touch. In climates with no frost, rhizomes can be left in the ground over the winter months. Mulching over the tops of plants during the coldest months of the year can help them to survive, as well. In areas with hard freezes, grow these plants in containers and move them indoors or to a more protected location over wintertime or dig them up each fall and replant them in springtime. Pruning is relatively straightforward for these plants; after they are done flowering and fruiting, cut back the flowering stem to the base of the plant. Any remaining foliage can be cut back in this way as well. New foliage and flowering stems will form and bloom in the next growing season. These plants will need to be divided every so often for ongoing health, especially when grown in containers. For instructions on how to successfully divide Arum lilies, see the Propagation section below. Arums are able to survive in the landscape for decades or longer provided with proper care, and will form clumps over time.
Caring for Arum in Containers
Although Arums grow very well in the ground, they also thrive in pots, which can allow for growers in cooler zones to grow these frost-sensitive flowers. Choose a pot that is a few inches wider and deeper than the original nursery pot or root ball. Choose a well-draining soil amended with plenty of organic material and perlite, and top with a dressing of mulch to increase soil moisture retention, suppress weed growth, and maintain a constant soil temperature. Water new plants regularly as they establish a strong root system in their new environment. Mature plants should be given water any time the top inch or two of soil feels dry to the touch. In cooler areas, move containers into protected areas during the winter months. Pruning is relatively straightforward for these plants; after they are done flowering and fruiting, cut back the flowering stem to the base of the plant. Any remaining foliage can be cut back in this way as well. New foliage and flowering stems will form and bloom in the next growing season. Repot when roots begin to grow through the drainage holes at the bottom of the container. These plants will need to be divided every so often for ongoing health, especially when grown in containers. For instructions on how to successfully divide Arum lilies, see the Propagation section below.
Propagation
Arum plants are most readily propagated via seed or division. To propagate your Jack-in-the-Pulpit, follow the instructions below:
Propagating Arum by Seed
Propagating Arum by Division
This type of propagation is relatively simple; you will need a clean shovel, mulch, fresh soil, compost and pots (only necessary if you will be saving divided plants for transporting elsewhere). Division is best done in spring or fall (after the plant has entered dormancy and been cut to the ground, but before it has begun its new spring growth), and needs to be done every four to five years regardless of whether you have the goal of propagating the plants for best performance, especially if you are growing Arum in containers. To propagate by division, follow these steps:
Propagating Arum by Seed
- Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. The best potting medium for seed germination is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
- Harvest your seeds. The seeds of Arum plants are located within the bright fruits held on the naked spadix after the spathe has faded. Cut the spadix off of the plant when the berries turn red in late summertime. Each berry contains 3 seeds, which can be gently squeezed out. After seeds are removed, rinse them to remove any remaining fruit flesh. Seeds are best when used fresh, and do not have a very long shelf life.
- Soak seeds for about 48 hours in warm water before planting, exchanging the water a few times during the soaking period when it cools down. After this process, remove seeds from their bath and lay them out to work with them.
- Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes between 4 and 8 weeks from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
- Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.
Propagating Arum by Division
This type of propagation is relatively simple; you will need a clean shovel, mulch, fresh soil, compost and pots (only necessary if you will be saving divided plants for transporting elsewhere). Division is best done in spring or fall (after the plant has entered dormancy and been cut to the ground, but before it has begun its new spring growth), and needs to be done every four to five years regardless of whether you have the goal of propagating the plants for best performance, especially if you are growing Arum in containers. To propagate by division, follow these steps:
- Using a shovel, dig up your existing plant. Start from the outside and work your way in to avoid damaging the tuberous roots. Once you have worked it up out of the ground, lay it out.
- Start to tease apart the roots with your fingers and rinse of any remaining dirt. Once the roots are untangled, separate your plant into segments, ensuring that each one has at least one growing point and a healthy root system.
- Prepare your pot(s) or new planting site(s) with amended, well-draining soil. You can either bring in new soil or simply amend your existing soil with compost to complete this task. Then, plant your divided tubers about an inch under the soil surface and water thoroughly.
- Apply a thick layer of mulch over the new planting to protect it from cold weather as it acclimates to its new home. Then, enjoy watching it sprout. Arum plants that have been propagated via root division typically take a few years to re-establish themselves and begin flowering again.
Problems and Pests
Arum plants are considered resilient in the landscape, though they can have issues with the following pests and diseases from time to time:
- Aphids
- Bacterial Soft Rot
- Root Rot
- Hawk Moth Caterpillar
- Spotted Wilt
- Dasheen Mosaic Virus
Gallery
These interesting flowers prefer some shade.
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Flowers are held on long stalks called spadices, surrounded by protective spathes that vary in color.
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After flowers fade, green berries take their place that mature to bright reddish-orange.
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Videos
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All about propagating Arum by seed.
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Identifying an Arum italicum plant.
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Resources
The New Sunset Western Garden Book: The Ultimate Gardening Guide (2012) - Page 172, Arum
