Native shrubs or small trees suitable for almost every garden, and pittosporums are grown for their foliage, Gillian Vine reports.
Among the most versatile small trees and shrubs for foliage are pittosporums, of which New Zealand has 26 species.
The name comes from two Greek words, pitta (pitch or tar) and sporum (seed), referring to the sticky seeds most have. That means the pronunciation is pitto-sporum, not pittos-porum.
All of our pittosporums are evergreen, making them ideal for hedges and privacy screens, shaping into feature plants in gardens and pots, and even as bonsai specimens.
Most are fast-growing but Pittosporum cornifolium is notably slower. It's an interesting plant for those who aren't in a hurry, as it is an ephiphyte, most often seen in the bush perching on big trees.
This species will also grow in well-drained soil, so not having a suitable host is no bar for the gardener.
The most common pittosporums are kohuhu (P. tenuifolium), found throughout New Zealand, except on the West Coast; tarata or lemonwood (P. eugenoides), with leaves smelling rather lemon-like when crushed; and karo (P. crassifolium), whose new shoots have white felting.
Growing to about 10m in height in the wild, tarata is New Zealand's tallest species, while kohuhu will quickly grow to about 6m, as will karo.
There is a long list of cultivars, the majority of which have been bred from P. tenuifolium, although Variegatum is a form of lemonwood with its notable feature the cream margins on its leaves.
P. tenuifolium varieties include some with splendid bi-coloured and tri-coloured leaves.
Among these are Deborah (similar to Variegatum in colour but with pink on the cream), Gold Star (gold and green leaves with cream along the midrib), Silver Magic (wide creamy margins), Tandarra Gold (small green and gold leaves) and Limelight (two-tone green).
To me, the best, though, is the exceptional Irene Paterson, whose leaves are white speckled with green. This variety is extremely popular in England, where our pittosporums and hebes are now standard fare in gardens in the southern parts of the country.
A North Island species, P. ralphii has been crossed with P. tenuifolium to produce the likes of Garnetti, whose variegated cream and white leaves are sometimes spotted with pink in winter.
Some reports suggest cultivars with P. ralphii as a parent may not be as tough as those bred from - or which are selected forms of - kohuhu alone.
Advances in breeding have produced cultivars with smaller leaves than kohuhu.
These shrubs are more attractive for hedging than older types, as pruning does not result in obviously chopped leaves, and are useful in any situation where frequent trimming is needed to keep plants shapely, such as topiary.
For containers, the leaf colour choices are almost as wide as is available in larger specimens.
Look for Pixie (silvery-grey leaves), Stirling Gold (yellow central stripe), Tiki (medium green), Golden Ball (green-gold leaves), Golfball (a pet that rarely needs clipping) or Tom Thumb (deep purple).
Like Purpureum, of which it is the dwarf form, Tom Thumb's young foliage is light green and changes to deep wine-red as it ages.
Dark-leaved pittosporums like these need to be carefully sited.
Surround them with plants having lighter foliage or pink flowers to show them off and remember that the more sun, the deeper the colour.
Although grown principally for their foliage, some pittosporums have sweetly scented flowers. Lemonwood, karo, Nelson's very rare P. dallii and two North Island species, P. umbellatum and P. turneri - the latter also rare in the wild - have perfumed flowers. Their scent is usually most obvious at night.
Overall, pittosporums are not too fussy about soil but undoubtedly do better in a sunny or semi-shaded spot where the soil is free-draining and reasonably fertile.
Generally pest and disease-free, they may get black spot or occasional mite attacks and rose spray is a good way to combat these.
Versatile and attractive, it's no wonder pittosporums have been moved out of the just-for-hedges bin and into the decorative-and-delightful category.
