How to Grow and Care for Blackberry Lily

Blackberry lily (also sometimes called leopard lily) is actually a species of Iris rather than a lily. It is a clump-forming plant that grows from spreading rhizomes, with flattened, strap-like leaves up to 10 inches long. In mid to late summer, wiry stems shoot up as much as 4 feet, with bright orange, red-spotted flowers with six petals. The flowers give way to pear-shaped seed pods which open in late summer to reveal blackberry-like seed clusters (the source of the common name).

Blackberry lily is normally planted in the spring from potted nursery plants or bare roots purchased from online sellers. They can also be planted from seeds, though it may take three years to achieve flowering plants in this way. Bare roots will generally mature into flowering plants in their first season, though it sometimes can take two seasons. Native to parts of India, China, and Russia, blackberry lily is a fairly short-lived perennial, and individual plants usually die out within a few years. But blackberry lilies spread easily, both from rhizomes and by self-seeding, creating an ongoing patch of plants.

All members of the Iris genus contain compounds that are mildly toxic to humans and pets.

Blackberry Lily Care

Here are the main care requirements for growing blackberry lily:

• Plant it in a location with lots of sun and well-draining soil.
• When planting bare rhizomes, space them about 3 to 4 inches apart (6 to 9 per square foot) and 5 inches deep.
• Water well until they are established. After that, give it modest but regular moisture and avoid excessive watering.
• Stake the long flower stalks if necessary to prevent them from blowing over in exposed locations.

Light

Choose a site with full sun to grow your blackberry lilies. A minimum of four hours a day is necessary for plant health and good blooms, and six hours is even better.

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.

Water

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.

Temperature and Humidity

Blackberry lily is generally considered hardy in USDA zones 5 to 10, though zone 4 gardeners often grow it successfully, as well. Hot weather and high humidity are not issues for cultivating the blackberry lily. The plants are not susceptible to mildews or fungi, provided no standing water is present.

Fertilizer

Supplemental fertilizer is not necessary to grow blackberry lilies. The plants are not heavy feeders, and can get the nutrients they need from the soil. In poor soils, a single spring feeding with a balanced organic fertilizer—or a synthetic fertilizer formulated for blooming plants—is sufficient. For the amount to use, follow product label instructions.

Types of Blackberry Lily

Until 2005, this plant was categorized as Belamcanda chinensis, and some sources may still list it under that name. But genetic sequencing demonstrated that this plant is an Iris species, and today is officially listed as Iris domestica. In addition to the pure species, there are two named cultivars commonly grown:

• 'Hello Yellow': This is a dwarf cultivar with leaves growing only 10 inches tall. The flower spikes rise to 20 inches, topped with unspotted, butter-yellow flowers.
• 'Freckle Face': This is a more prolifically blooming version of the species plant, producing as many as 12 blossoms per plant.
  

Blackberry lily is not a common offering at most garden centers, so you may need to seek out a specialty nursery or purchase from online retailers, who sell either rhizomes or seeds.

Pruning

Although blackberry lily does not require "pruning" in the formal sense, removing the seed capsules as they form will prevent them from ripening and casting seeds into the garden, where you will need to pluck out the volunteers.

Pruning the flower stems after they fade may help prolong the bloom period with new blossoms. Cut back blackberry lily at the end of the growing season. Remove the yellowing foliage to tidy up the garden and eliminate fungal spores and nesting areas for pests.

Propagating Blackberry Lily

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:

1. Using a shovel or garden fork, carefully dig up plants.
2. Use a sharp knife to cut apart pieces that have a fan of foliage attached.
3. 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.
4. 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.

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 Lily

Growing blackberry lilies in containers is a great way to "stage" the plants when they come into bloom: Before blooming, place the containers in an out-of-the-way spot, as the foliage is not much to look at. When the blooms begin, move the containers to a prominent spot on the porch or patio where you can enjoy the flowers.

Plant up two or three blackberry lilies in the same pot to give a full look. Use well-drained potting soil in any container with good drainage. Arrange the rhizomes close to the soil's surface so that they are not touching. Divide and repot the lilies as they expand and become crowded. Repot in late summer, when growth slows down.

In most climates (freezing temperatures and snowfall), dormant plants in their pots can usually be stored in a sheltered but cool outdoor area for the winter. Zone 5 gardeners, however, may find that potted blackberry lilies perish over the winter unless moved into a garage or basement, as plant roots are more vulnerable when they are above ground in pots.

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.

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.

How to Get Blackberry Lily to Bloom

Bloom Months

Blackberry lily blooms in July to August. 

How Long Does Blackberry Lily Bloom?

Under ideal conditions—and when deadheaded regularly—it can bloom for several weeks but blackberry lily blooms only last a day or two. 

What Do the Blackberry Flowers Look and Smell Like?

The lily-like flowers are deep orange with lots of red spots. The flowers have no noticeable floral fragrance.

How to Encourage More Blooms

If your blackberry lily is not blooming, it can usually be traced to one of several reasons:

• Plants are too young. It's not uncommon for newly planted rhizomes to not flower until their second year, and plants started from seeds may be shy until their third year.
• Not enough sun. Like most iris, blackberry lily needs at least four hours, and preferably six or more hours, of direct sunlight each day in order to produce ample blossoms.
• Too much fertilizer. Unlike many flowering plants, blackberry lily prefers to get its nutrients from naturally rich soil. Too much artificial fertilizer can actually cause fewer flowers. At most, these plants should be fertilized once in the spring with organic fertilizer or flower fertilizer. More than that may lead to disappointing results. 

Caring for Blackberry Lily After It Blooms

Blackberry lily does not require any care after blooming but it is recommended to remove the flower stalks before they can turn into seeds and disperse to prevent the blackberry lily from reseeding—unless you would like to leave the seed pods on the plant for winter interest. 

Deadheading Blackberry Lily Flowers

Deadheading of blackberry lily is encouraged because it will promote additional blooms.

Common Problems With Blackberry Lily

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.