Hesperantha

( hess - per - ANTH - uh )

At-A-Glance Information

This genus of flowering perennials includes species which grow from rhizome and are commonly called Crimson Flag or Scarlet River Lily. Species are native to South Africa and need full sun to light shade and regular to ample waterings for best performance and blooms. Crimson Flags has sword-like leaves and star-shaped flowers held on tall stems that are excellent in fresh arrangements. Use these flowers as members of cut flower or pollinator gardens, in mixed beds and borders, around water features, or in bog or rain gardens.

Hesperantha Species and Varietals

The genus includes 79 species and is a member of the plant family Iridaceae. Formerly called Schizostylis, Crimson Flag grows well in USDA hardiness zones 7-9 or Sunset growing zones 5-9 and 14-24, H1 and H2. To find your zone, click here: Zone Map.

Hesperantha coccinea (Schizostylis coccinea) (River Lily, Crimson Flag Lily)
This semievergreen perennial species is native to southern Africa and Zimbabwe. It reaches up to 16 inches tall when mature and in bloom, and produces green strappy foliage. This species is considered invasive in northern California and southwestern coastal zones of the United Kingdom. Popular cultivars are listed and described below:

'Alba'
With white flowers on a plant that is more compact.

'Cindy Towe'
With deep red blooms.

'Jennifer'
With larger flowers that are pale pink with light centers.

'Major'
Robust form featuring large, crimson-red flowers.

'Mrs. Hegarty'
Soft, pale-pink flowers that bloom early.

'November Cheer'
Dark pink flowers bloom late and continue into fall.

'Rosea'
With rich pink flowers.

'Sunrise'
Mid-pink to orange flowers.

Caring for Hesperantha

Plant Crimson Flag in a space in the landscape that receives full sun and is somewhat sheltered. Set rhizomes a foot apart and 0.5 to 1 inch deep in organically enriched well-draining soil. They prefer soil to have a pH of between 6.1 and 7.8. If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost before installing. Water newly planted Crimson Flags regularly to help them develop strong root systems. At maturity, these plants need generous amounts of water during their active growing and blooming seasons, though in their dormancy (late fall and winter) they do not need supplemental irrigation. Apply a thick layer of mulch to the planting area after installing; this will help to suppress weed growth, maintain soil temperatures, and increase soil moisture retention.

Fertilize yearly in early springtime with a application of 2 inches of compost around the base of plants. Pull mulch back before applying, work the compost gently into the soil a bit, water it in, and then replace mulch. These plants are not heavy feeders, and this should be sufficient to provide the necessary nutrients for the active growing and flowering seasons. Pruning these flowering plants is simple: remove spent blooms and any unsightly foliage. Clumps can become overcrowded; if this occurs, divide them in early springtime, leaving at least five shoots on each division. Typically, they need to be divided every two to three years, especially when grown in containers or other confined spaces. For instructions on how to divide Crimson Flag, see the Propagation section below. Grow these flowers in pots in areas where winters are cold, so that they can be brought into a more sheltered location during the winter months. These flowers can survive in the landscape for many years; they will form clumps over time, providing new flowers for the garden indefinitely.

Caring for Hesperantha in Containers
Hesperantha rhizomes do well in the ground, but can also be grown in containers, which is an option that allows for gardeners in cooler zones to grow these beauties. Choose a container that is at least 12 inches wide and deep. Ensure that the pot has adequate drainage holes on the bottom to allow for excess water to flow away. Fill with a well-draining potting mix amended with organic material and perlite, and top with a layer of mulch to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. Water regularly as the plant establishes itself in its new home. Once established, waterings can be lessened. Hesperantha plants grown in containers will need more frequent irrigation than those grown in the ground. As a general rule of thumb, water whenever the top few inches of soil feels dry to the touch, and withhold waterings when plants are dormant in late fall and winter. Prune to remove dead, damaged, or diseased foliage at any time during the growing season. Every few years, check the bottom of the pot to ensure that the plant is not outgrowing its root space. If roots are growing through the drainage holes in the bottom of the container, it is a good indication that it needs to be potted up; choose a slightly larger container and repot.

Propagation

Hesperantha, or Crimson Flag, can be propagated either by division or from seed. To ensure that your propagated plant will have the exact same qualities and characteristics as the parent plant, use the division method. If you would like to experiment and see what plant you can grow from seed, just keep in mind that it will not necessarily be the same as the parent plant. To propagate your Crimson Flag, follow the instructions below:

Propagating Hesperantha 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 seed heads on plants are pretty easy to spot, they're left behind after flowers have faded. Once they have dried out and begun to split open, you can harvest the seeds inside. Cut them off of the plant, placing them in a paper bag. Harvest as many as you can, and place the paper bag in a dry, cool, dark area. They will continue to split open and release the seeds contained inside. Once they have been released, take them out of the bag and put them in a container so you can work with them.
In either late winter or early springtime, get your container prepared. 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 2-6 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 65 and 72 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 Hesperantha 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 very early spring (after the plant has entered dormancy, but before it has begun its new spring growth), and needs to be done every few years regardless of whether you have the goal of propagating the plants for best performance. 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 root(s). Once you have worked it up out of the ground, lay it out.
Start to tease apart the roots with your fingers. Once the roots are untangled, separate your plant into segments, ensuring that each one has at least one thick root section attached.
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 divisions 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 in the next growing season.

Hesperantha seed pods.

Hesperantha seeds are typically small and light brown to tan in color.

Problems and Pests

Certain species are considered invasive in some regions; see the species descriptions above for more information. Check with local authorities before planting. Hesperantha flowers are typically free of pest and disease issues in the garden, though they can have problems from time to time with: