Fountain butterfly bush

Fountain butterfly bush: how do you recognise it?

Habit

Broad shrub with long, arching branches, 3 m tall and 3 m wide; can also be trained as a standard.

Leaf

Narrowly lance-shaped, 4–10 cm, grey-green, arranged alternately on the branches rather than in opposite pairs.

Flower

Small, lilac flowers in dense clusters along the previous year’s branches, in June.

Scent

Sweet and honey-like, especially on warm days.

Branches

Thin, supple and arching; they flower on the previous year’s wood.

Flowering: June · Plants: March–April and October–November · Pruning: July

Why grow it?

• A spectacular fountain of lilac flowers in June, like a weeping willow in bloom.
• A true bee and butterfly shrub with a sweet, honey scent.
• Drought-tolerant and happy with poor, chalky soil in full sun.
• Lovely as a specimen, on a bank or trained as a standard with a weeping crown.
• Fully hardy and rarely troubled by disease.

Fountain butterfly bush: where does it grow best?

• Full sun: in shade it hardly flowers.
• Well-drained soil: sand, loam or clay, acid to chalky. On poor soil it stays more compact.
• Dry to moist; it does not like wet feet in winter.
• Allow 3 m of space so the branches can arch freely. As a standard, about 2 m is enough.

Light

Sun

Soil type

Sand, loam or clay

Acidity

Not fussy

Moisture

Dry or normal

Size

3 m tall, 3 m wide

Hardiness

Hardy (to -25 °C)

Goes well with

• Lavender: Another bee plant for sun and drought; the purple shades go well together.
• Catmint: Low, long-flowering underplanting in the same lilac shade.
• Shrub roses: Flower in June together with the butterfly bush.
• Ornamental grasses: Fine stems beside the arching branches, attractive well into winter.

Fountain butterfly bush: when and how to plant it?

Plant in March–April and October–November.

1. Plant in March–April or October–November.
2. Dig a planting hole twice as wide as the root ball; on heavy clay, mix in coarse sand or grit.
3. Set the plant at the same depth as in the pot and firm the soil well.
4. For a standard, put in a sturdy stake straight away and tie in a single straight stem.
5. Water generously straight away, and in dry spells during the first year.
6. Mulch the base with gravel or wood chips.

Care

Watering

In dry spells during the first year; after that rarely needed.

Feeding

Little: some compost in spring. Too much feed gives lots of leaves and floppy branches.

Mulching

A layer of gravel or wood chips keeps weeds down without making the soil too wet.

Support

A standard needs a sturdy stake for the first few years.

Pruning

Every year straight after flowering, so new branches grow to flower the following year.

Tip: In a small garden, grow it as a standard: the branches hang down like an umbrella and there is still room for plants at its feet.

Fountain butterfly bush: when to prune it?

Pruning months: July.

When: Straight after flowering, in late June or July. Never in spring, or you cut off the flower buds.

How:

• Cut flowered branches back to a strong, young side shoot lower down the branch.
• Each year remove a few of the oldest branches at the base to keep the shrub open and young.
• On a standard, shorten the flowered branches so the crown does not get too heavy, and remove shoots on the stem.
• Cut out dead and weak branches.

Caution: It flowers on the previous year’s branches: pruning in spring, as you would the common butterfly bush, costs you the whole display.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Softwood cuttings

In June–July, take 8–10 cm cuttings from non-flowering shoots and put them in moist cutting compost under plastic. They root easily.

Semi-ripe cuttings

In August–September, take heel cuttings and overwinter them in a cold frame or under glass.

Fountain butterfly bush: how does it get through the winter?

Hardy to −25 °C.

• Fully hardy to about −25 °C: no protection needed in Belgium.
• Wet soil in winter is more dangerous than frost: make sure drainage is good.
• A standard in a pot spends the winter against a wall, with the pot wrapped in hessian.

Diseases and pests

• Few flowers: Usually caused by pruning in spring or by too much shade. From now on prune after flowering and give it full sun.
• Red spider mite: Fine yellow speckling on the leaves in hot, dry summers. Hose down with water.
• Aphids: On young shoots in spring. Natural predators usually deal with them.
• Untidy shape: Without pruning the branches become a tangle. Thin the shrub after flowering.
• Root rot: On wet, heavy soil. Plant in a free-draining spot.

Through the year

• March: Plant. Add a little compost.
• April: Plant. Tie in a standard.
• May: Buds swell along the branches.
• June: Full flower, with bees and butterflies. Take softwood cuttings.
• July: Prune straight after flowering. Take cuttings.
• August: Water during long droughts. Take semi-ripe cuttings.
• October: Plant.
• November: Plant.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Butterflies

Nectar for butterflies.

Did you know?

• Unlike almost all other butterfly bushes, its leaves are alternate rather than opposite; that is what the name alternifolia refers to.
• The genus Buddleja is named after Adam Buddle, an English clergyman and botanist of the 17th and 18th centuries.
• The British plant hunter Reginald Farrer brought it from China to Europe in the early 20th century.