Libertia
( li - BUR - shuh )
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At-A-Glance InformationThis genus is commonly known as New Zealand Island Iris or New Zealand Satin Flower, and includes species that form fans of sword-like foliage topped with white flowers in late spring through the middle of summer. Provide these plants with light shade in the warmest climates of its zone range, and water regularly for best performance. Use these architectural plants in modern, coastal, and low-water use garden spaces.
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Libertia Species and Varietals
Libertia is a genus in the plant family Iridaceae and includes 17 accepted species. They are closely related to plants in genera Orthrosanthus and Sisyrinchium. The best growing zones for Libertia are USDA hardiness zones 8-11 or Sunset growing zones 8, 9 and 14-24. To find your zone, click here: Zone Map.
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Libertia grandiflora (New Zealand Satin Flower, New Zealand Iris, Mīkoikoi, Tukauki) Broad, bright green leaves clump together to form a 2-foot tall, 1.5 foot wide plant. White flowers bloom in clusters atop stems 2.5 feet tall. This species is native to New Zealand, and grows well in USDA hardiness zones 8a-11. |
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Libertia ixioides (New Zealand Iris, Mikoikoi) Narrow-leaved species with central light green to orange stripes on each leaf. Cultivars include 'Goldfinger' (with a yellow-gold central leaf band), and 'Taupo Blaze' (pictured, with leaves that turn shades of pink, orange and green in fall; produces orange berries). This species grows well in USDA hardiness zones 7-10. |
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Libertia peregrinans (Orange New Zealand Iris, Orange Libertia, Mikoikoi) Reaches 2 feet tall and a foot wide, with erect olive green leaves. Central stripe on leaves is brown-orange, and shines when backlit. Flowers are held on stems shorter than the leaves. Variety 'Bronze Sword' reaches 1-1.5 feet tall. |
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Caring for Libertia
Choose a space in the landscape that receives full sun to partial shade during the day. Ideally, these plants should be getting between 6 and 8 hours of direct sun each day for best flowering and performance, but do appreciate a good amount of shade in the late afternoon when temperatures are at their peak. They prefer to be planted in well-draining, moderately fertile soil with a pH of between 6.0 and 7.0 (slightly acidic to neutral). 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 Libertia flowers regularly to help them develop strong root systems. At maturity, these plants are drought-tolerant, able to get by on rainwater alone with some supplemental waterings in the warmest months of the year. Mulch around the base of plants to increase soil moisture retention, suppress weed growth, and maintain consistent soil temperatures.
Fertilize yearly in early springtime with an 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 is simple; remove flowering stems as they fade if desired. At the end of the flowering season is the best time to prune the entire plant. At this time, remove all spent flowering stems and clean up any dead, damaged, or diseased foliage. These flowers are considered to be long-lived perennials, and can survive in the garden for 5-10 years before needing to be replaced. Plants will form clumps over time, however, providing new flowers for the landscape indefinitely.
Fertilize yearly in early springtime with an 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 is simple; remove flowering stems as they fade if desired. At the end of the flowering season is the best time to prune the entire plant. At this time, remove all spent flowering stems and clean up any dead, damaged, or diseased foliage. These flowers are considered to be long-lived perennials, and can survive in the garden for 5-10 years before needing to be replaced. Plants will form clumps over time, however, providing new flowers for the landscape indefinitely.
Propagation
Libertia 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 New Zealand Iris, follow the instructions below:
Propagating Libertia by Seed
Propagating Libertia 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:
Propagating Libertia 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 14-28 days 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 Libertia 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.
Problems and Pests
Libertia plants are susceptible to developing issues with the following pests and diseases in the landscape:
- Slugs & Snails
- Aphids
- Spider Mites
- Root Rot
- Leaf Burn
Gallery
Libertia lines this garden pathway with whimsical white blooms.
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Libertia fills in empty spaces in mixed beds and borders with evergreen architectural clumps of foliage.
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Videos
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Learn about these garden ornamentals.
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Libertia are great low-maintenance plants for urban settings.
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Resources
The New Sunset Western Garden Book: The Ultimate Gardening Guide (2012) - Page 410, Libertia
