Buddleia (Buddleia davidii) -- also known as butterfly bush -- is a large shrub with a pleasant, round shape and small, showy flowers that decorate the plant from summer to autumn. Allow plenty of space, as buddleia can grow to heights of 3 metres (10 feet) with a spread of up to 2.4 metres (8 feet). The fragrant blooms -- available in shades of purple, lavender, lilac, pink, yellow or white -- attract honeybees, hummingbirds and butterflies.
Plant buddleia in full sunlight and well-drained soil. Make sure the plant is in the shade during the heat of the day and in a location protected from cold winter winds.
Pile 15 cm (6 inches) of mulch around the base of the shrub in autumn to protect the plant against winter freezing and thawing. Remove the mulch in early spring. Although the plant may die back in winter, it will return quickly in spring if the shrub's roots and crown are protected.
Keep the soil lightly moist for the first year, but never allow the soil to become waterlogged. After that time, give the buddleia 5 cm (2 inches) of water per week during warm, dry weather, then allow the soil to dry before watering again. Buddleia is a drought-tolerant plant that won't do well in soggy soil. During winter, water the shrub occasionally to keep the soil from becoming bone dry.
Clip off spent blooms during the season to encourage healthy growth and continued blooming. Cut the blooms as desired for indoor bouquets.
Prune buddleia hard in late winter or early spring, leaving only 25 cm (10 inches) above the ground. Trim the shrub lightly in mid-June to remove any growth that detracts from the plant's shape and appearance.