Blue lechenaultia (Lechenaultia biloba) is a member of the goodeniaceae family. There are approximately 30 other species within the genus Lechenaultia, most of which are native to western Australia.
In its native habitat, it grows on hillsides and grasslands. It thrives in sunny areas with sandy or gravelly, well-drained soil.
In the United States, blue lechenaultia is hardy only in USDA hardiness zones 9-11. It is lightly frost-tolerant and grows as a perennial only in the warmest climate zones.
This small, woody sub-shrub has a semi-sprawling growth habit. Older stems become woody while younger stem growth is softer and green. The leaves are tiny and evergreen. They are densely packed along the stem, resembling the leaves of rosemary.
Masses of beautiful blue flowers appear in the winter and spring. The color ranges from deep rich to pale purplish-blue. Flowers are 5-petaled, and each petal divides into two distinct lobes, giving rise to the species name biloba.
Blue lechenaultia is drought tolerant and an excellent choice for container gardening, a rockery, or a xeriscape. If this sounds intriguing, let’s dig deeper into the natural history, care, and maintenance of the blue lechenaultia.
Blue Lechenaultia Plant Overview
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Plant History
This colorful Australian shrub thrives in warm climates.
These small shrubs display an array of colorful flowers, including white, yellow, red, and shades of blue. A few of these species have become popular with gardeners. All prefer warm, arid climates.
Blue lechenaultia is native to the dry regions of southwestern Australia. It grows in poor-quality, sharply-drained soil.
It blooms in the late winter or spring, providing early-season color. The evergreen foliage keeps the garden interest year-round.
Cultivation
The shrub is easy to propagate by cuttings.
Blue lechenaultia is a short-lived plant, living only 4 to 6 years in ideal conditions. It is easy to propagate by cuttings, so you won’t have to worry about losing your plant entirely. Established plants will also spread by suckers emerging from the base.
Blue lechenaultia is only slightly frost-tolerant. In most of the United States, it grows best as a container plant. Bring it in for the winter months and allow it to grow outside in the summer.
Lechenaultia is low-growing and somewhat sprawling. It makes a good ground cover for a small area. Grow it in a rock garden, xeriscape landscape, or in a more controlled environment, such as a large raised bed, container, or hanging basket.
Propagation
Lechenaultia is easiest to grow from cuttings. You can start it from seed, but success rates may be low as the seeds require special treatment to sprout. Depending on where you live, you may also be able to find nursery-grown plants in specialty nurseries or sold through online growers.
Seed
Growing Lechenaultia from seed can be challenging.
Lechenaultia is difficult to grow from seed. To simulate their natural environment, the seeds may need to be scarified and heat-stratified before planting to encourage them to sprout. Research shows that nicking the seeds with a knife and exposing them to high-temperature smoke improves germination by 81%.
If you try growing lechenaultia from seed, sow seeds on the soil surface and keep the soil moist and warm until they sprout. Be patient with this process, as it may take your seeds several weeks to show any signs of life.
Seedlings
Transplanting Lechenaultia seedlings requires a gentle hand to avoid damage to the young plants.
If you successfully grow lechenaultia from seed, you will have seedlings to transplant directly into your garden or grow in a hanging basket or container. Keep them in a warm environment with bright light and minimal soil moisture.
The seedlings can be fragile. Carefully handle seedlings and rooted cuttings to avoid unnecessary damage to the stems and leaves.
Cuttings
Propagate Lechenaultia through cuttings and grow it indoors during winter.
Lechenaultia cuttings are easy to root. If you have access to a lechenaultia plant, take semi-hardwood cuttings in the late spring or summer with this simple process:
- Use sharp shears to take cuttings of fresh and healthy-looking stems 3 to 4 inches long.
- Dip the lower 2 inches in a rooting hormone. If using powdered rooting hormone, dip the cut end of the stems into water to dampen them, shake off excess, then roll the cut end in the rooting hormone.
- Place the lower part of the stem in moist soil.
- Keep the soil only slightly moist.
- Ensure the plants have good light and plenty of air circulation.
Once your cutting develops healthy roots, you will notice it growing new leaves. When new leaves form, you know your cutting was a success, and you can allow the soil to dry between waterings. Keep your new plant in a warm, dry, sunny location until you can transfer it to a larger container or outside for the summer.
If you are growing lechenaultia as an annual in your garden, you can take cuttings each fall before the first frost. Root the cuttings indoors and grow them as houseplants through the winter months.
In the spring, when the temperature has warmed and all danger of frost has passed, you can transplant these young plants outside to enjoy another summer growth season. Take cuttings again each fall, and you can keep your lechenaultia going indefinitely using this method.
Planting
Plant this shrub outside in full sun with well-drained soil after the danger of frost has passed.
After all danger of frost has passed, plant your cuttings or seedlings outside in full sun with other flowers that enjoy sandy well-drained soil. Prepare your site in advance to be sure the soil has excellent drainage and your plant has plenty of space to grow without interference from weeds or close neighbors.
When you are ready to plant, use a spade or hand trowel to dig a hole and carefully transfer the root mass into the hole. Fill the gaps around the roots with fresh soil and gently pat it down around the plant.
How to Grow
Growing this flowering shrub is straightforward as long as it has ample sunshine and dry, well-drained soil.
Sunlight
Lechenaultia prefers full sun and needs at least 6 hours of direct sunlight daily.
Lechenaultia grows best in full sun but is tolerant of light shade. Aim for at least 6 hours of direct sunlight each day.
If you are taking your plant in for the winter, give it the sunniest window location you can. Those in the northern hemisphere should try to provide a south-facing window as that will have the most winter sunlight. A grow light can be used if a south-facing window is not available.
Water
These drought-tolerant shrubs need well-draining soil to thrive, whether indoors or outdoors.
These shrubs are drought-tolerant and require well-draining soil to thrive. The soil should never stay wet, soggy, or saturated, but it should remain barely damp to the touch, as that’s the ideal moisture level.
If growing it as a houseplant, allow the soil to dry between waterings. If you are growing it outdoors for the summer months, you should not need to do any supplemental watering.
Soil
Well-drained and slightly acidic soil is ideal.
The ideal soil pH for lechenaultia should be somewhat acidic, between 5.5 and 6.5. Do not attempt to grow these plants in heavy clay soil or poorly drained soil, as the roots are very prone to fungal root rot in wet conditions. Add sand, gravel, or perlite to help improve drainage if necessary.
Climate and Temperature
They prefer warm, dry climates and need good air circulation to prevent humidity-related issues.
Lechenaultia plants can survive a very light frost but are generally considered frost-sensitive. Lechenaultia does not tolerate high-humidity environments, so it is best grown in a more arid climate.
Place your plant in a location with good air circulation. If possible, to reduce the chance of built-up humidity, which can lead to fungal diseases.
Fertilizer
Enhance plant growth with seasonal organic fertilizer, adjusting usage based on soil quality.
Adding organic fertilizer each spring and fall can boost your plant’s growth. Use a well-balanced fertilizer for houseplants or outdoor flowering plants, and follow the manufacturer’s directions for the product you use.
When growing in soil that is already nutrient-dense, your plant may not need any extra fertilizer. However, supplemental fertilizer is useful when growing in poor, sandy soil mixes.
Maintenance
Pruning after flowering promotes compactness and enhances flowering beauty, while mulching protects roots and controls weeds in summer.
Prune your lechenaultia to keep it compact. If you do prune your plant, do so after flowering so you can maximize its flowering beauty.
Pruning will encourage your plant to stay more compact and tidy looking, isn’t necessary to maintain health. Add some mulch around the base of the plant to help control weeds and protect roots from scorching in the summer sun.
Varieties
This unique flowering shrub comes in several cultivars to fit your garden aesthetic.
‘White Flash’
This cultivar has deep blue flowers with a white splash, easily propagated by cuttings.
This beautiful Australian cultivar has deep blue flowers with a distinctive white splash in the center of the lowest three petals. This popular variety is easy to propagate from cuttings.
White Lechenaultia galactites
This species is a small, attractive shrub with white flowers suitable for frost-free xeriscaping.
This white Lechenaultia species grows to 24 inches tall and sports white flowers. This small shrub looks rather scraggly with many-branching twigs and sparse leaves.
The pure white flowers, however, are quite attractive. This would be an excellent small shrub for a frost-free xeriscape.
Red Lechenaultia formosa
The Red Lechenaultia is a popular variety with vibrant scarlet-red flowers.
Red Lechenaultia has vibrant scarlet-red flowers. The flowers have a different petal arrangement than the blue Lechenaultia, but they are equally as dazzling.
Yellow Lechenaultia linarioides
This yellow variety is a small shrub with pale yellow flowers that attract pollinators in winter and spring.
Yellow Lechenaultia is a small shrub that grows to 4 feet tall. It has pale yellow flowers with pink accents. Grow this plant in full sun in a frost-free location with sandy, well-drained soil. The flowers bloom in winter and spring and attract pollinators.
Wildlife Value
This plant attracts pollinators and is an excellent addition to a pollinator garden when grown outdoors while blooming.
Blue Lechenaultia attracts pollinators, including bees, butterflies, and other insects. If you are growing these plants indoors over the winter and they are blooming indoors, there won’t be much wildlife value, but if they are outdoors while blooming, they make an excellent addition to a pollinator garden.
Pests and Diseases
Fortunately, only a few ailments affect this plant.
Root Rot
They are susceptible to root rot due to their preference for well-draining soil.
Lechenaultia needs extremely well-drained soil and is prone to fungal root rot. Wet and poorly drained soil will lead to fungal development in the growing media, resulting in rotting root tissues and a host of other ills.
Ensure your container and soil drain excess moisture well; it should remain damp to the touch but should not be muddy or oversaturated. Avoid leaving containers sitting in saucers of water for similar reasons.
Powdery Mildew
Prevent fungal infections through improved air circulation and avoiding leaf water spray.
These plants thrive in arid climates. High humidity or moisture on leaves can easily lead to powdery mildew and other fungal leaf infections. Watch for discoloration of the leaves, a white dusty-looking powder on leaves, or leaves that wilt or drop.
Improve air circulation around your plants, keep them in a dry environment, and if you hand water your plants, don’t spray water on the leaves. Damp leaves provide an ideal environment for airborne fungal spores to cling to.
Insect Pests
You should regularly check for aphids and spider mites to control insect pests.
Lechenaultia plants are generally not bothered by insect pests. If there are aphids or spider mites in the area, they may occasionally move over to feed on the leaves.
Watch for visible insects and leaf damage caused by insects. Mist all plant surfaces with neem oil to help control infestations, and act quickly to control the infestation so it cannot spread to neighboring plants.
Frequently Asked Questions
Final Thoughts
Blue Lechenaultia is a beautiful, showy little plant perfect for a xeriscape garden. It will thrive in ideal conditions, with full sun, low humidity, and gritty, well-drained soil. It is easily propagated by cuttings, and it makes a great low-growing ground cover for small areas. Consider growing it along a walkway or in a container.
Unfortunately, this plant is not tolerant of freezing temperatures or prolonged moisture in the air or the soil, making it difficult to grow in less-than-ideal conditions. If you have the right conditions, however, blue Lechenaultia can bring great joy to the garden!
