Buddleja
Buddleja L.
Buddleja (Buddleja L.) is a genus of flowering shrubs and trees belonging to the Scrophulariaceae family. Native to tropical and subtropical regions across Asia, the Americas, and Africa, these plants have become staples in temperate gardens worldwide.
What the section contains
Asian butterfly-bush
Buddleja asiatica Lour.
Buddleja alternifolia
Buddleja alternifolia Maxim.
Buddleja crispa × marrubiifolia
Buddleja crispa Benth. x Buddleja marrubiifolia Benth.
Buddleja davidii
Buddleja davidii Franch.
Buddleja hybrid
Hybrids between Buddleja alternifolia Maxim. and Buddleja marrubiifolia Benth.
Buddleja lindleyana
Buddleja lindleyana Fortune
Buddleja loricata
Buddleja loricata Leeuwenb.
Buddleja luteolufaucia
Buddleja x luteolufaucia
Buddleja pikei
Buddleja x pikei H. R. Fletcher
Curly butterfly bush
Buddleja crispa Benth.
Fallow's buddleia
Buddleja fallowiana Balf. f. & W. W. Sm.
Globe buddleia
Buddleja globosa Hope
Hybrids of Buddleja alternifolia and Buddleja davidii
Hybrids between Buddleja alternifolia Maxim. and Buddleja davidii Franch.
Weyer's butterfly bush
Buddleja x weyeriana Weyer
Woolly butterfly bush
Buddleja marrubiifolia Benth.
Buddleja
Optimal growth requires full sun exposure and well-draining, fertile soil. Buddleja is sensitive to "wet feet," meaning that soil drainage is critical to prevent root rot, especially during dormant or winter periods.
The plant thrives in temperate climates, though hardiness varies by species. It requires consistent moisture throughout the growing season, but once established, some varieties show moderate drought tolerance.
Agricultural practices focus on heavy annual pruning. Because Buddleja blooms on new wood, cutting back the previous year's growth in early spring is essential to ensure vigorous flowering and a manageable plant shape.
Economically, Buddleja is highly valued for ornamental use and its role as a pollinator magnet. Often called the "butterfly bush," its nectar-rich flowers are essential for supporting local populations of butterflies and beneficial insects.
The primary threats to Buddleja are fungal infections induced by excessive humidity and poor air circulation. Leaf spot and grey mold (Botrytis) are common issues that typically appear during cool, wet springs.
Pest pressure is primarily driven by sap-sucking insects. Spider mites are the most significant pest, thriving in hot, dry conditions and causing leaves to yellow and drop prematurely.
Good cultural practices, such as proper spacing during planting and removing dead or diseased wood, are the first line of defense. Ensuring that the foliage stays dry reduces the risk of fungal proliferation.
When chemical intervention is necessary, the use of targeted acaricides and insecticides is recommended to keep mite and aphid populations under control without harming the butterflies attracted to the plant.
Winter protection, including mulch or burlap wrapping in colder zones, helps protect the base of the shrub. This ensures that the root system remains viable, allowing the plant to regenerate effectively the following season.