Blackberry lily (Iris domestica) is a herbaceous perennial that grows from 61 to 91 cm tall. The leaves of the plant grow in fans, similar to those of a gladiolus. It is also called a leopard lily due to its big orange flowers. The blooms are showy and will blossom from summer to early fall. It needs full sun and well-drained soil for optimal growth.
I. Appearance and Characteristics
Iris domestica, commonly known as leopard lily, blackberry lily, and leopard flower, is an ornamental plant in the family Iridaceae. In 2005, based on molecular DNA sequence evidence, Belamcanda chinensis, the sole species in the genus Belamcanda, was transferred to the genus Iris and renamed Iris domestica.
The plant is native to Eastern Asia and has been cultivated worldwide in subtropical and temperate climates. Due to the ornamental value of its attractive flowers, the plant was distributed to Europe as early as the 18th century and the United States and Caribbean countries in the 19th century.
A perennial herb, I. domestica may grow to a height of 0.6–1 meter (2 ft 0 in – 3 ft 3 in), with its rhizomes in shallow ground, extending horizontally. It has 3-5-stems and 8-14 leaves per stem growing in a fan, with flowers ascending proximally having orange-red scattered spots of darker pigment, blooming during summer. The seed pods open in the fall, showing clusters of black, shiny seeds whose resemblance to those of a blackberry gives the plant its common name, “blackberry lily”. The plant is hardy to USDA plant hardiness zone 5 and is propagated by seeds or division.
In the wild, it grows in grasslands, pastures, forest clearings, meadows, and mountainous regions or shrublands. Although it has escaped cultivation in many regions, it is not considered to have potential as an invasive species.
II. How to Grow and Care
Sunlight
For the best flower production and overall plant health, blackberry lilies should be planted in full sun with exposure to at least 6 hours of sunlight each day.
Temperature and Humidity
Blackberry lilies are considered hardy in USDA zones 5 through 10 (and occasionally zone 4). Their ideal temperature range is from 65ËšF to 75ËšF. When the thermometer climbs above 80 degrees, your blackberry lilies may wilt and show signs of stress. In temperatures below 50 degrees, blackberry lilies will likely go dormant.
Blackberry lilies are also tolerant of high humidity levels (ideally between 40% and 60%), but should not require additional atmospheric humidity if the soil is kept consistently moist.
Watering
While blackberry lilies respond to regular watering by producing larger, healthier blooms, they are also drought tolerant. Dry winter soils are ideal. Err on the side of less water, not more. If your garden is getting rain every week or two, extra irrigation is rarely necessary. During drought periods, 1/2 inch per week is entirely adequate. Water should be cut back during the dormant winter months to discourage root rot.
Soil
Having the perfect soil isn’t important for growing blackberry lilies, but having good drainage is. Soggy soils, especially in winter, can cause the rhizomes of blackberry lilies to rot. These plants are not fussy about soil pH; they will do well in both slightly alkaline, neutral, and slightly acidic soil conditions (pH 6.1 to 7.8). Poor soils tend to make the plants shorter; in rich soils, they will be taller.
Fertilizing
Blackberry lilies do not require supplemental fertilizer in most soils. In fact, adding fertilizer may lead to overfertilization, which can cause yellowing, crispy or curling leaves, and brown spots.
Planting Instructions
To plant blackberry lily seedlings and bare root plants, wait until spring (after the danger of frost has passed) and dig a hole twice the size of the plant’s root ball. Place a mound of soil in the bottom of the hole and carefully spread the roots over the mound. Cover the roots with soil, tamping the dirt down as you work. Water thoroughly. If you are planting more than one blackberry lily, place them 6 to 10 inches apart.
If growing your blackberry lilies from seed, start them indoors in late winter 10 to 12 weeks before the last frost. You can also sow the seeds directly into the ground in early spring, but be patient. Germination may take several weeks.
Pruning
Blackberry lilies do not require pruning, but it’s wise to remove the seed pods as they form if you wish to prevent self-seeding. You can also prolong the blooming season by deadheading spent blooms as they fade.
Propagation
Similar to the way that iris or daylily rhizomes can be divided, you can propagate blackberry lilies in the same way—by digging and dividing the root clumps. This is best done when the flowering is over and the plants are mostly done growing—in late summer or fall. Here’s how to do it:
- Using a shovel or garden fork, carefully dig up plants.
- Use a sharp knife to cut apart pieces that have a fan of foliage attached.
- Inspect the root pieces for soft or rotted areas, which can indicate damage from iris borers, cut away any of these spots, leaving only firm root sections.
- Replant the pieces in the desired locations, spaced at least 4 inches apart.
- Division every few years will also help keep the clump healthy, as individual plants are not long-lived without regular division.
Growing Blackberry Lily From Seed
You can easily grow blackberry lily from seed. In the fall, collect the seeds once the seed pods have become dry and papery. A sign that they are ready is when the seeds inside the pod are rattling. Try to cut off the seed pods before they break open on their own and disperse the seeds; otherwise, you might have to collect them off the ground.
Cold stratification of the seeds significantly improves the germination. Stratified seeds usually germinate in 1 to 2 weeks. Chill the seeds in the refrigerator for 4 to 8 weeks or direct sow them outdoors in a well-marked location anytime between fall and late winter and nature takes care of the stratification.
If starting them indoors, sow the seeds in mid- to late winter in a seed-starter mix, covering them with 1/4 inch of mix. Keep the pots well-watered in a bright location until the seedlings sprout. Move them to a sunny location and continue to grow them, watering when the soil gets dry. When the weather warms in the spring, move the pots outdoors and continue to grow them until they are well established. At this point, they can be transplanted into the garden.6
Blackberry lily self-seeds quite easily, and it is an easy matter to transplant some of the tiny volunteer seedlings to new locations.
Potting and Repotting
Blackberry lilies also make excellent container plants—especially if you wish to curtail their spreading habit. In the spring (when temperatures are above freezing). choose a container with good drainage and fill it partially with a well-draining potting mix. Spread the roots over the soil and add more potting mix, tamping it down to secure the plant. Ideally, your plant should sit 1/2 to 1 inch below the rim of the container. Water thoroughly and continue to water regularly as your blackberry lily takes root. If growing from seed, plant your seeds just 1/2 inch deep in the prepared container. Keep the soil evenly moist and germination should begin in a few weeks. Keep your container-grown blackberry lily in a sunny spot and move it to a protected location if temperatures dip below 50˚.
Since blackberry lilies are rhizomatous perennials that readily self-seed, they may occasionally outgrow their pot. Plan to repot or divide yours every 2 to 3 years. The best time to do this is in the spring or early fall when the plant is no longer flowering. When you are ready, carefully dig up the entire root system. Inspect the roots for signs of disease or iris borers (soft, often foul-smelling rhizomes) and separate the root clumps with a sharp knife. Replant the entire blackberry lily in a larger container or place the healthy, separated root systems in separate pots. Water well and place in the sun.
Overwintering
Most gardeners will not find it necessary to give these plants any winter protection against cold, though if you are trying to cheat the standard zone recommendation by growing blackberry lily in zone 4, then a winter layer of mulch may be a good idea.
The black seed berries on this plant can be attractive in winter, so many gardeners allow the flower stalks to remain as snows arrive. This will, however, encourage self-seeding in the garden, so if this is not to your liking, then it’s best to clip off the flower stalks before they can go to seed.
Pests and Diseases
Common Pests & Plant Diseases
Blackberry lilies are generally trouble-free plants. However, the common iris borer can infect and even kill plants. The pest is insidious and may leave no signs at first except an entry hole at the base of the plant. If your plant looks wilted or discolored, look for this hole. Remove and destroy any infected plants, roots and all. Root sections can be salvaged by closely inspecting them and cutting away any rotting sections or areas with borer holes.
Root rot may occur if blackberry lily is grown in soil that does not drain well, or if the plant gets too much water. This is a common problem in extremely wet climates. Badly affected plants will need to be removed and discarded.
Common Problems
Other than iris borer and root rot caused by excessively moist conditions or dense soil, blackberry lily is a relatively problem-free plant. Some gardeners find themselves disappointed by the shorter bloom period and rather subtle display. This is not a great plant for gardeners looking for spectacular long-lasting color, but it can be ideal for those looking for interesting diversity in the garden.
The most common problem is that the tall flower spikes can be prone to toppling over in windy conditions, so it is best to stake them, especially in exposed locations.
III. Uses and Benefits
Blackberry lily provides early to mid-summer color as it blooms to reveal bright orange and red-spotted flowers. This plant species is grown easily from seeds. The blackberry lily is most often planted on perennial borders within gardens. It is valued for its low maintenance requirements along borders in addition to its showy blossoms.
IV. Harvesting and Storage
Blackberry lily flowers can be harvested for bouquets. Choose not-fully-bloomed flowers and cut them off from the stem base obliquely with a pair of sharp gardening scissors. Quickly put the flower in a vase with clean water to avoid its dehydration.
