Buddleja is an easy to grow, summer flowering garden shrub. Buddleja vary in that they can be evergreen, semi evergreen and deciduous. There are three main types found growing in the UK which are hardy. B. globosa,illustrated in the center image, B.alternifolia illustrated right and B davidii illustrated right. The most commonly grown is B.davidii(image above left) which is deciduous. Buddleja davidii is fast growing and a large shrub, up to 5m with 5 m spread, and best kept in check by pruning.
Buddlejas are grown for it's lovely panicles of flowers, often scented, and which are attractive to insects and butterflies. Each panicle has hundreds of tiny flowers and the flower panicles are large so that a Buddleja in bloom is a showy sight. In fact, Buddleja are a butterfly magnet and in the summer can attract many butterflies and are definitely one of the top 10 plants to grow to bring butterflies into the garden. B.davidii is fully hardy suitable even for cold exposed areas and also for coastal gardens. Buddleja has many attractive flowering colours all ranging around mauve, pink.purple and white and well known varieties are : B 'Black Knight' which is dark purple, 'White profusion,' 'Harlequin' pink which also has variegated leaves, and 'Empire Blue'. All Buddleja davidii are fragrant. Buddleja requires no real attention to survive and is not fussy as to soil types, growing especially well on chalk and lime soil, and it is easily grown even on poor soil. Buddleja alternifolia, which is also deciduous, and has lovely scented lilac coloured flowers in early summer .
There is signficant variety in the size of Buddlejas, some such as the popular 'Black Knight' spread quickly and can reach 3 meters, but there are many species which are more compact, and dwarf and patio varieties been developed all the time, such as B. 'Nanho Blue'.
Buddleja's common name is 'Butterfly bush' and rightly so. In the summer it is full of butterflies, bees and insects. The images above shows just how attractive the Buddleja is to butterflies, top left is one flower with three peacock butterflies on it all at once. If you grow Buddleja in your garden you will be able to enjoy butterflies flitting around. A good combination is to plant Buddleja with Oregano and Sedum and create a butterfly paradise.
Recently Buddleja has had a bit of a bad press as being invasive because it does self seed, and this can be a problem if your garden is near an area of natural beauty or conservation. If this is a concern it is easy to dead head the flowers which will prevent it from setting seed.