How to grow buddleja: all you need

This week...

How to GROW

WITH GRAHAM RICE

Buddleja

The butterfly bush is a summer-flowering shrub that’s popular with pollinators

The intense colour of ‘Royal Red’ adds drama to late-summer borders – to get the best of out any buddleja, prune in spring when green shoots appear

BUDDLEJA, commonly known in some parts as the butterfly bush, is a strong-growing, deciduous, flowering shrub producing large colourful cones of flowers in summer and autumn. Each flowerhead is made up of a number of tiny individual flowers that produce large quantities of nectar and so are popular with butterflies and other insects.

Buddlejas are tolerant shrubs, easy to grow and easy to prune. And while old

There’s a good range of modern buddleja varieties to choose from, including the Miss Series varieties can produce a heavy crop of seeds that help the plants become invasive in mild areas, in recent years safe-to-plant modern varieties have been developed that produce no seeds at all.

Perfect low-maintenance plant

Experts at Wayside Gardens in the USA point out: “Butterfly bushes are a great addition to almost any garden, attracting butterflies and other beneficial pollinators in droves. Also known as buddlejas, these are large, dense bushes featuring big, majestic flower spikes that bloom in intense hues of pink, orange, red and purple throughout the summer. Several cultivars have great drought tolerance, making them the perfect lowmaintenance plant for the back of a mixed-border planting. ”

How to choose a butterfly bush

FIRST, decide if you need a modern noninvasive type in your garden. Then consider the final size. The Lo & Behold series is ideal for patio containers, while plants in the Miss Series are taller and more suitable for mixed borders, shrub borders and as specimens.

Lo & Behold ‘Blue Chip’ is suitable for containers

Where to buy

Crocus crocus.co.uk 01344 578 000 The Lavender Garden thelavenderg.co.uk 01453 860 356 Thompson & Morgan thompson-morgan.com 0333 400 0033

Two kinds of butterfly bush

THERE are two kinds of buddleja and it’s important to know the difference.

Modern buddlejas

MODERN varieties of buddleja have mostly been developed in North America with the aim of producing neater, more compact growth that is suitable for smaller gardens. It is especially important that many modern varieties produce no seed and are not invasive.

Modern, non-invasive varieties of buddleja include the dwarf Lo & Behold Series and the taller Miss Series, both in four different colours, and the Flutterby Series (pictured) of seven varieties in a range of heights and colours.

Buddleja ‘Flutterby Pink’

Buddleja Buzz Series ‘Velvet’

Planting advice

BUDDLEJA need at least six hours of sun each day, with all-day sun being preferable, and they will grow thin and spindly and flower very poorly under trees. Any reasonable well-drained soil suits them, but they appreciate thorough preparation before planting, so improve the soil with garden compost or bagged multipurpose.

Plant in spring or early to mid-summer, soaking the rootball in a bucket of water while you prepare the site. After planting, mulch with 2-3in (5-7.5cm) of bark chips or other weed-free material to conserve soil moisture and prevent weed growth.

In containers, choose a well-drained planting mix and stand the container on pot feet to lift the pot just off the ground and allow surplus moisture to drain away quickly, otherwise the roots will rot.

Old-fashioned buddlejas

THE old-fashioned varieties of buddleja tend to be the tallest and the most vigorous. They are often prolific in flower and produce a great deal of nectar to feed pollinating insects.

Old-fashioned buddleja varieties can also produce a huge number of seeds and may become invasive. Many were developed here in England where, until recently, invasiveness was not a problem, but they may be listed as invasive in some parts of the US. Varieties in this group include the English Butterfly Series and the shorter Buzz Series, both in a wide range of colours, as well as individual varieties including ‘Black Knight’ and ‘Royal Red’ .

When growing in containers, allow excess water to drain by adding pot feet

Top care tips

THE most important care that a butterfly bush needs is deadheading. As soon as the flowers have turned brown, snip them off. Immediately behind the dead flowerhead you will usually find a short shoot with a cluster of flower buds at the tip. Cut just above that shoot to spur it into opening its flowers.

Deadheading is important because it dramatically improves the look of the plant. The display from white-flowered varieties, in particular, is often ruined by the presence of the brown seedheads from the earlier flowers. Deadheading also prevents the plant wasting energy in producing seeds when it is the flowers that are important.

F u t u r e Deadhead as the flowers begin to turn brown

Frequently asked questions

How do I propagate buddleja?

BUDDLEJA can be grown from seeds, but the results are very rarely a match for named varieties bought as plants. Once you have a named variety in your garden, you can make more by taking cuttings in spring or summer.

Make cuttings by snipping off the tips of the growing shoots to give you a cutting about 4-6in (10-15cm) long. Recut just below the lowest leaf joint, snip off the leaves on the lowest half of the cutting and insert into pots of fresh, moist potting soil so that the lowest leaves are just above the soil. Cover with a clear plastic bag and keep in a light, but not sunny place. Move the cuttings into individual pots when the roots start to emerge from the drainage holes.

Cuttings root quickly – when large enough, transplant into individual pots Choose a modern variety bred to be compact, such as Flutterby ‘Petite Blue Heaven’

How do I grow buddleja in pots?

Butterfly bushes do well in containers, but it is important to choose the right variety and look after it correctly. Choose only modern varieties that remain small and will not drop seeds that will sprout between the cracks in your paving. Varieties in the Lo & Behold Series are ideal. Choose a large container, 18-24in (4560cm) across, and place it in a sunny position on three pot feet to ensure good drainage. Part fill with fresh, damp,

How to GROW

WITH GRAHAM RICE

Conservative spring pruning to 2-3ft (60-90cm) encourages bushy growth

How to prune

1Buddleja produces its summer flower spikes on growth that develops earlier the same season. So, to encourage the most growth and the most flowers, pruning is done in spring, just as the buds on the old branches are starting into growth.

2Some gardeners prune very hard, cutting off all growth to about 6-12in (15-30cm) above the base. The result is relatively few, very vigorous, fast-growing shoots carrying long fat spikes of flowers.

3Pruning less severely, to about 2-3ft (60-90cm) will encourage far more shoots to develop, creating a bushier look, with many smaller flower spikes.

Water during dry spells to avoid problems

potting soil and set the plant in place so that its compost is about 1in (2.5cm) below the rim of the container. Add more potting soil and firm well around the roots leaving a level finish. Mulch with gravel or bark chips and then water in well with a liquid feed. Keep moist all summer, deadhead regularly, then, in colder areas, move the pot to a sheltered pace for the winter. Prune in spring, then move back to a sunny site.