How to Grow Buddleia Bushes (Butterfly Bushes)

How to Grow Buddleia Bushes (Butterfly Bushes)

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Buddleia bushes are one of my favourite shrubs and whether love them or hate them, the butterflies love them as they’re full of nectar which is why they get the name butterfly bushes. Pollinators such as butterflies, moths, and bees find themselves lured by the bright beautiful blossoms that vary in colour depending on the variety.

They are probably one of the easiest of all shrubs to grow and you could even get away with providing no care but with a little pruning in spring, they really do come into their own. They are so easy to grow that they are considered an invasive species in many parts of the world and you often see them growing from brick walls, railway lines and even wasteland.

Buddleia can be invasive and grow from brick walls, wasteland and rail tracks
Violet blossom of buddleia flower over railways.

Once grown in the garden though, thats when they really come into their own with the most attractive displays of spiked flowers and smothered in butterflies and bees.

Growing buddleja in your garden will add beauty to the garden in late spring and summer while attracting pollinators to help plants in the garden pollinate.

Most buddleias, especially the davidii varieties can grow very tall, as tall as 8ft to 10ft in a single season even with pruning. However, you can also get more compact dwarf varieties of buddleia such as the Buzz and Chip varieties that can grow between 3-4ft. These smaller growing varieties are perfect for growing in pots and containers which I also have a guide on here

Let’s begin with the perfect conditions for cultivation:

Suitable growing conditions for buddleia

Buddleia growing well in garden border

Buddleia are not too sensitive to the environment and thus, will survive in pretty much any climate, especially in the UK and most of the US. They need adequate sunshine to thrive, the more the better and free-draining soils to prevent issues such as root rot. If you have clay soil I recommend mixing in some organic compost and grit into the hole to help with drainage.

These plants grow in clay or loam as long as the PH is not extremely acidic or alkaline. A pH of 5.5-8 works fine as long as the soil has adequate nutrients. Regular watering of the plants keeps them hydrated but for potted plants, avoid watering daily and allow the surface of the soil to dry out between watering.

Even though they are hardy, I recommend giving them a little protection by avoiding planting them in open spaces where summer gales can snap the long branches, especially with the tall growing varieties.


Hard pruning Buddleia with loppers

Pruning is essential in maintaining the appearance of the plant and encouraging new growth. You should carry out pruning in spring around April or May or autumn depending on the variety. Globosa and a couple of other varieties prune on the current year’s growth so they need pruning lightly after flowering. Pruning these varieties hard will remove the flowering stems which will lead to no flowers.

You can leare more about what varieties to prune when here.

Caring for your buddleia

Buddleias are not demanding plants therefore they are about as low maintenance as shrubs get.

All you need to do is follow the tips below:

  • Give the plants enough water especially in summer when temperatures rise. If you have potted buddleia, make sure the drainage holes are unobstructed to prevent water pooling around the roots.
  • Fertilising the plant occasionally will boost the soil’s nutritional level but be careful not to over-fertilize. Bombarding the plants with nitrogen-rich fertiliser will encourage more foliage rather than blooms. Feed with a high potash feed in spring after pruning, this will encourage more pruning.
  • Provide the plant with mulch to help maintain soil moisture and maintain soil temperature, especially when it is cold.
  • Deadheading buddleia blooms in summer and spring is essential in encouraging the plant to bloom throughout the flowering season but also to stop the spead of unwanted plants.

Deal with problem

Because these plants have a lot of foliage, spacing them is vital in maintaining proper ventilation that prevents fungal infections such as sooty mould. Also, watch out for Japanese beetles and caterpillars that may attack the plant. Note down the symptoms the plant is displaying, find the root cause, and provide immediate treatment. Most pests can simply be controlled with a pesticide from your local garden centre or nursery. Sooty mould and fungus can usually be controlled with a fungicide.

You can read more about common pests and diseases that attack buddleias here

You can also learn why your buddleia might be wilting here

Propagating buddleia – Different methods

I explain step by step how to take Buddleia cuttings including softwood in spring and hardwood in autumn.

You have the option to cultivate buddleia through seeds, cuttings, or dividing the roots. All these methods work, just pick the one you would prefer.

Cultivating buddleia from cuttings

Taking cuttings from mature plants is a good way to propagate these plants to get little identical plants. With cuttings, you don’t have all the wait assisted with sowing their seeds it doesn’t take nearly as long to grow a decent sized plant.

Take softwood buddleia cuttings in summer or spring from new soft growth a few inches long, cut at an angle just below a leaf node, and replant them immediately for them to take root before winter sets in.

Cuttings must be of a suitable height of three inches and the lower leaves removed. The removal of the lower leaves gives more space for rooting nodes to emerge and prevents the plant from being too close to the ground.

Using a rooting hormone is optional but, ensure that the compost is moist. The cuttings must remain hydrated to produce new growth, and this also goes for hardwood cuttings harvested in autumn.

Learn more about how to take buddleia cutting in my guide here

Looking for a fast growing shrub, check out my recommended shrub here for filling in spaces

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