Butterfly tree: planting and care

Where to plant butterfly trees?

Buddleias are easy-going flowering bushes. With a versatile character, they can be used almost anywhere in the garden, as standalone plants, in perennial borders, in sunny rockeries, and in flowering pots for dwarf varieties or grouped in free hedges.

To bloom generously, they need to be planted in full sun, ideally along a wall in a location that is not too windy, to protect their rather brittle stems, especially when weighed down by the weight of the floral spikes.

Butterfly trees are content with any soil, even poor quality, the only requirement being that it is well-drained. Soil that is too rich would encourage foliage at the expense of flowers. In deep soil, they will show increased drought resistance.

They need a location that suits their size: with a rapid growth rate, the larger varieties will quickly form vegetative screens over 6 m high and nearly as wide. Buddleias are easy to plant and associate with all sorts of other sun-loving bushes and perennials that are similarly low-maintenance, such as Ceanothus, Lavateras, Tamarisks, Symphorines, and shrubby Potentillas…

When to plant?

The planting of Buddleias is carried out according to the climate, either in autumn or in spring. In warm and dry regions, autumn planting is preferred, ideally in September-October, and at the latest in December. In colder or wetter regions, planting should be done at the end of winter, ideally in March-April.

Buddleia davidii ‘Pink Delight’, like all butterfly trees, is planted in autumn

How to plant Buddleias?

Buddleias are among the easiest bushes to grow. They are not demanding regarding soil type and can thrive even in mediocre soil.

To stagger the flowering periods, you can group several varieties together. Flowering occurs as early as the first summer. Maintain a density of 1 bush per m². For hedge planting, a spacing of 80 cm to 1.20 m should be respected.

Buddleias simply need sunlight to bloom well and perfectly drained soil to prevent their roots from rotting.

Planting in the ground

• Dig a hole that is deeper than it is wide and loosen the soil well.
• If the soil is clayey, place a thick layer of gravel at the bottom of the hole for drainage.
• Position the bush well in the centre at the bottom of the planting hole.
• Backfill with garden soil mixed with potting soil in equal parts.
• Firm the soil around the base of the bush and water.
• To encourage recovery, lightly trim the shoots (to about 20 cm in length).
• Fertiliser is not necessary, especially since overly rich soil may promote foliage growth at the expense of flowering.

Planting in a pot

Some dwarf varieties of Butterfly Bush, such as Buddleia ‘White Chip’ or ‘Nanho Blue’, are perfectly suited for pot cultivation.

• Choose a sufficiently large terracotta container for the bush to develop well (minimum height of 60 cm).
• Ensure perfect drainage with clay balls, pumice, bark fragments, cocoa shells, etc.
• Install the Buddleia and cover with a mixture of leaf potting soil (three-quarters) and garden soil.
• In pots, nutrient reserves deplete quickly: to stimulate flowering, add 1 to 3 handfuls of organic origin fertiliser (decomposed manure, compost, horn, etc.) once a year in spring.
• Plant a ground cover plant or maintain a mulch at the base of the bush to help keep the soil moist in summer.
• Water regularly during the first summer, twice a week, and very little in winter.
• Repot every year into a larger container.

Maintenance, pruning and care

The more you prune a Buddleia, the more generous, bushy, and vigorous it will become!

Butterfly trees require little maintenance.

Water newly planted specimens during the first summer to encourage rooting. After that, only water in case of prolonged heatwaves. When grown in pots, they need more attention: fertilise twice a year to promote flowering and provide regular watering in summer.

The secret to keeping beautiful Buddleias is pruning, as unpruned shrubs will eventually become sparse, flower less, and take on a scraggly habit. Buddleia davidii, in particular, requires severe pruning; do not hesitate to cut back hard in March, before the vegetation starts again, to 50 cm above the ground: Buddleias flower on the wood of the year, so the upcoming flowering will not be threatened but rather stimulated! Pruning also encourages the regrowth of branches and helps maintain an elegant habit, not bare at the base.

→ Read also: Diseases and pests of Buddleia – butterfly tree.