Buddleja davidii is also called butterfly bush and autumn lilac. This is because the flowers look a bit like the flowers of the lilac. It's a large shrub that mainly attracts butterflies. This shrub has violet-blue flowers. It originally comes from China. In Europe, this shrub is mainly used as a garden plant. This plant is frost-resistant to about -10 C °. In the spring, before the butterfly bush starts to flower (April) it can be pruned to about 50 cm from the ground. This ensures exuberant flowering and a refreshment of the bush. After flowering, for example in October, the shrub can be pruned to remove the old flowers and leaves. This should be done less rigorously.
The butterfly bush can be cultivated by taking cuttings or sowing seeds. Taking cuttings is very simple: Put the tops of cut branches into moist soil in the spring. Make sure these tops are about 20 cm long. Don't let these buds dry out. About 6 weeks later, new leaves will start to form. Because this butterfly bush can withstand sea wind, it's an ideal plant for people who live near the coast and want to attract butterflies. It flowers from July to September. Hardy perennial. Height: 250 - 300 cm.
Indoor sowing: the whole year round
Germination: 7 - 14 days
Germination temp. : 20 - 24 C°
Sowing depth: shallow
Planting distance: 100 - 120 cm
Plant position: sunny - half shade and sheltered
Flowering period: in the second year after sowing June - October
It's fairly easy to grow the butterfly bush yourself. Sowing indoors is possible all year round. Provide a large pot or a seed tray filled with moist sowing soil. Sow the seeds thinly and superficially. Press the seeds gently. Don't cover the seeds as the butterfly bush is a light germinator. Light and warmth are necessary for good germination. Keep the temperature as even as possible and don't let it drop at night. The butterfly bush needs a lot of warmth, light and high humidity to germinate properly. Cover the trays or pots with a lid or some plastic to keep the moisture in and the seeds from drying out. Place the trays or pots in a light place, but not in direct sunlight. After 7 - 14 days the seeds germinate.
Remove the lid or plastic once the seeds have germinated. This way the seed is ventilated. Once the seedlings are large enough to handle, pot them into small separate pots. Put the butterfly bush seedlings in a slightly less warm room (18 C°). Water sufficiently and don't let the seedlings dry out. Keep them free of weeds. Protect the seedlings against frost. The seedlings grow fast and must be planted out at the intended spot before growth starts in the 2nd year. This is usually done in April. The plants flower from July to October. After this, they should be cut back to about 75 - 100 cm. Before flowering in April, it's good to prune the shrub hard to about 50 cm from the ground. This stimulates the growth of leaves and the flowering of the flowers. Very productive plants may even flower in the first year.
