Pittosporum are shrubs or small trees with fine, glossy evergreen foliage that are particularly suited to mild areas and seaside gardens in the UK. Elsewhere they are at the limits of their hardiness, and need the shelter of a wall or to be grown in pots in the cool greenhouse or conservatory. But clients should not be put off from trying them. Frost damage can be cut out and they respond well to pruning.
There are around 200 species of Pittosporum but trade in the UK focuses mainly on P. tenuifolium and P. tobira. They are among the hardiest of the species, tolerating temperatures as low as -10 degsC.
P. tenuifolium is prized by gardeners and flower arrangers for its glossy foliage, which often has wavy edges. It also produces tiny, purply-brown flowers, which are honey-scented, although being given out only at night this is often overlooked.
There is an impressive range of tenuifolium varieties, taking in large and small forms. Some have dark leaf stems and there are many leaf variegations. Some of the best have contrasting young and mature foliage, such as 'Tom Thumb', probably its most popular cultivar.
As the name suggests, it is a dwarf type, reaching a maximum height of 1m, and its juvenile foliage is light green above older purple leaves, creating a striking effect in the garden. Another popular variety is 'Irene Paterson', with its green and white marbled leaves.
P. tobira Award of Garden Merit (AGM) is another good landscape plant. It is also known as the Japanese mock orange, and does resemble Choisya with its white flowers and mid-green leaves. But the foliage is distinctively leathery and rounded at the ends. Its creamy white flowers, produced from late spring to early summer, are sweetly scented.
Pittosporum like well-drained soil. The variegated cultivars and P. ralphii and R. crassifolium - which both make good hedges alongside P. tenuifolium - prefer full sun, while all other species will tolerate light shade. They need to be sheltered from cold and drying winds and benefit from an annual mulch.
They can tolerate hard pruning in spring if it is necessary to remove frost-damaged growth. Some like to keep their Pittosporum a bit looser and only give an occasional trim or remove certain shoots from the woody framework. But the shrubs can be closely clipped in midsummer if this is the look preferred. They shed their older leaves in late spring, which can alarm clients. This merely precedes a flush of new growth.
What the specialists say
- Charles Williams, owner, Burncoose Nurseries, Cornwall
"The genus Pittosporum provides a huge range of attractive evergreen foliage plants, with every sort of variegation customers might desire. They are a great background to a border.
"The one that sells best is 'Tom Thumb', a dwarf type with attractive new growth against dark-purple leaves that can be used in a border or in a pot.
"Many Pittosporum plants were damaged by frost last winter, but it was the coldest for 20 years. They can be pruned back and will sprout readily.
"My favourite is P. tenuifolium 'Limelight'. It is a vigorous, medium-sized shrub with wonderful gold leaf colour."
- Simon Lord, branch manager, Johnson's of Whixley, Chobham, Surrey
"Pittosporum is a good structural plant for sheltered positions. Garden designers love it - the key to its popularity is its interesting foliage and form. For me the variety P. tobira 'Nanum' stands out, because of its wonderfully scented flowers.
"Pittosporum really need a well sheltered position. Many plants were hit badly by the extreme cold during last winter and availability from nurseries is limited this spring as a result."
- Graham Hutchins, owner, County Park Nursery, Essex
"Though Pittosporum are reasonably hardy, last winter was rough and we lost several. One of the variegated types that came through well was P. tenuifolium 'Tandara Gold'.
"But it is young plants that are at risk. Once they are established they will make it through. They tolerate pruning well.
"Generally semi-shade is ideal, although some types like a bit of sunshine - it brings out the colours best in the variegated types."
- Dan Bowyer, director, Fisher Tomlin
"In our projects we have most often used P. garnettii. It has a nice silvery-white variegated leaf that makes it a great backdrop for other plants.
"Soft purple and blue flowers really stand out in front if it. We also use P. tobira - very different with a deep-green colour and thicker leaves. It also looks great at the back of a border and copes with shade.
"I recommend planting them as single specimens or in groups of three or five - not more, because they can get quite big. For this reason they don't suit a small border, but in a large border they are excellent, behind herbaceous perennials or bulbs."
Species and varieties
- P. eugenioides 'Variegatum' AGM (H3) is a tender variety that is best grown in a conservatory in the UK and taken out onto the patio in summer, when it produces fragrant star-shaped flowers. It becomes a small tree and has glossy, variegated leaves that give off a lemony scent when crushed. Height: 5m. Spread: 2m.
- P. 'garnettii' AGM (H3) forms a large, spreading bush featuring grey-green leaves with cream margins. They are spotted pink or red in winter. Small, honey-scented flowers are produced in spring.
- P. tenuifolium AGM (H3) is a frost-hardy, evergreen bushy shrub or small tree with green, glossy, wavy-edged leaves on dark stems. Small purply-brown, honey scented flowers are produced in late spring and early summer.
- P. tenuifolium 'Abbotsbury Gold' is a frost-hardy, large bushy evergreen shrub, featuring greeny-yellow leaves with green margins. Like other variegated varieties it fares best in full sun. Provide shelter from cold drying winds in frost-prone areas.
- P. tenuifolium 'Elizabeth' is an attractive evergreen shrub bearing wavy green leaves with white margins tinged with pink. Height: 3m. Spread: 2m.
- P. tenuifolium 'Gold Star' has leaves that are yellow-tipped when young but become completely variegated. Plant in a spot that is sheltered form cold drying winter winds. Fine in milder spots of the UK.
- P. tenuifolium 'Irene Paterson' AGM (H3) is one of the most popular varieties alongside 'Tom Thumb'. It is a compact bushy shrub bearing creamy young leaves, which are later deep green, marbled with white and flushed pink in winter.
- P. tenuifolium 'Loxhill Gold' is a compact shrub with gold variegated foliage. Suited to a warm sheltered spot in sun or part shade.
- P. tenuifolium 'Margaret Turnbull' is a compact variety featuring dark-green leaves with a central splash of golden yellow.
- P. tenuifolium 'Purpureum' is an evergreen shrub bearing pale green leaves that gradually turn rich dark bronze-purple. Height: 2-3m.
- P. tenuifolium 'Silver Queen' AGM (H3) has attractive white markings on the edges of its leaves. Small, bell-shaped purple flowers are produced in clusters during late spring and early summer.
- P. tenuifolium 'Tandara Gold' has small golden variegated leaves, on very dark stems. Grow in a well drained soil in a sunny or part-shaded situation.
- P. tenuifolium 'Tom Thumb' AGM (H3) is one of the most popular varieties. It has neat, wavy evergreen leaves that are golden-green when young, later turning bronze-purple.
- P. tobira AGM (H3), the Japanese mock orange, has dark-green, leathery leaves and sweetly-scented creamy white flowers from late spring to early summer.
- P. tobira 'Variegatum' AGM (H2-3) is a popular form with attractive green and cream variegated foliage and creamy white flowers in spring.