Lochinch butterfly bush (Buddleja fallowiana) is a hardy shrub with a robust stature, recognized by its lance-shaped, silver-grey leaves and dense clusters of delicate, sweet-scented lavender to purple flowers. These blooms are a magnet for butterflies and bees during their summer peak. Originating from high-altitude regions, lochinch butterfly bush is adapted to cooler climates, thriving in well-drained soils with full sun exposure.
I. Appearance and Characteristics
Buddleja fallowiana is a species of flowering plant in the figwort family Scrophulariaceae. It is endemic to the Yunnan province of western China, where it grows in open woodland, along forest edges and watercourses. The plant was collected in China by the Scottish botanist George Forrest in 1906, and named in 1917 by Balfour and Smith for George Fallow, a gardener at the Royal Botanic Garden Edinburgh. Fallow had died in Egypt in 1915 from wounds sustained fighting in the Gallipoli Campaign.
Buddleja fallowiana is a deciduous shrub typically growing to a height of 4 m (13 ft). Of loose habit, the plant has young shoots clothed with a dense white felt. The ovate to narrowly elliptic leaves are 4–13 cm (1.6–5.1 in) long by 1 cm (0.39 in) wide, acuminate or acute at the apex; the upper and lower surfaces densely tomentose, bestowing a silvery grey sheen. The inflorescences are slender, thyrsoid, sometimes interrupted, with panicles at the ends of the current year’s shoots. The flowers are 5–15 cm (2.0–5.9 in) long by 2–3 cm (0.79–1.18 in) wide, comprising fragrant lavender blue flowers with orange throats, the corollas 2 – 3.5 mm wide by 9 – 14 mm long with erect lobes. The flowers bloom in late summer and autumn.
Growth is significantly slower than that of B. davidii; Bean considered the species more closely allied to B. nivea, although its chromosome number, 2n = 76 (tetraploid), places it alongside the similarly tetraploid B. davidii.
Somewhat tender, B. fallowiana is best grown against a wall. However, if cut to the ground by frost, it will grow again from the base. Hardiness: USDA zones 8–9.
II. How to Grow and Care
Lochinch butterfly bush thrives in full sun and requires well-drained soil to prevent root rot. It’s drought-tolerant once established, making it low-maintenance. Pruning in late winter helps maintain shape and encourages prolific blooming. Overwatering should be avoided to protect its root system.
Sunlight
Lochinch butterfly bush prefers full sun. A minimum of 8 hours of bright sunlight is required if many blooms are desired. Do not plant under trees since too much shade will affect its growth.
Temperature
Some hybrids of genus Buddleja are less tolerant of cold temperatures. Towards the fringes of their range of hardiness, they may act more like a herbaceous perennial and die back to ground level during the winter. Their rapid growth means this should not pose a problem to blooming. Alternate-leaved butterfly bush (B. alternifolia) is a good choice for cold areas, as it has more hardy roots than most others.
Watering
Originating from high-altitude regions, lochinch butterfly bush is accustomed to less frequent hydration, thriving in well-drained soil conditions. Its water habits are marked by a preference for moderate moisture without the need for constant wetness, showing a resilience to sporadic watering. In cultivation, it benefits from watering once every 1-2 weeks, ensuring that its roots do not sit in excess water. Typically grown outdoors due to its size and attraction for pollinators, lochinch butterfly bush flourishes when rain patterns align with its growth cycles, promoting vigorous flowering during its active season.
Soil
Lochinch butterfly bush prefers neutral to alkaline soils that are rich in nutrient. It will tolerate alkaline soils of up to 8.5, ideally within the range of 5.5-7.0. It can cope with most types of soil, even chalk, and is able to grow in coastal areas, as it is tolerant of salt. It doesn’t like heavy clay.
Fertilizing
Though lochinch butterfly bush can tolerate poor soils, the addition of fertilizer will improve growth and quantity of blooms. Using a good quality rose fertilizer is a good choice, as it will usually have a high potash (potassium) content, which encourages flowering.
Another alternative is to use fish, blood, and bone meal with the addition of homemade wood ash. Using the meal on its own would be too high in nitrogen and would result in strong growth. If many blooms are desired, the ash is a necessary addition.
Planting Instructions
Lochinch butterfly bush should be planted once the soil has warmed and the last frost has passed. Late spring or early summer would be a good time of year to plant. Dig a hole two to three times wider than the plant’s root ball (a little deeper, if additions are being used). Additions include compost, fertilizer, and limestone chippings.
Limestone chippings are not essential, but can help to keep the plant from suffering due to low pH if the surrounding soil is acidic. It can also improve drainage. Compost can be used to improve the structure of the soil and improve drainage in heavy clay soils.
The use of fertilizer when planting means that the plant should not require more fertilizer for a year or two. Applying it around the roots makes it very accessible to the plant. If the plant must be moved, the best time is late autumn or early winter. At this time, they are not in a period of rapid growth, so are more able to deal with the changes.
Pruning
Pruning should be carried out in early to mid-spring. Earlier in the spring will allow more time for lochinch butterfly bush to recover, which should result in more blooms. Cut back flowering stems from the previous year to within 1-2 buds of the older, woodier framework of the plant. Remove any thin, dead, or weak growth. Cutting the plant annually back to around 61 cm in height will keep the plant from getting too large.
If the plant is in an exposed and windy site, reduce its height by about half in the autumn to avoid wind damage. Alternate-leaved butterfly bush and orange ball tree both flower on the previous year’s growth, so spring pruning would likely reduce the number of flowers that year. These types benefit from pruning after flowering. Deadheading regularly will encourage flowering.
Propagation
Lochinch butterfly bush is excellent at self-propagation from seed, so much so that in some areas it has become invasive. Not all hybrids are like this; some have been bred to be sterile to combat this problem. Seeds can be sown indoors in the early spring, and planted in late spring or early summer, once the final frost has passed. Cuttings are also a viable method of propagation.
III. Uses and Benefits
Lochinch butterfly bush can be used as cut flowers. It has a honey-like fragrance. Cutting the flowers also encourages the plant to produce more blossoms.
