The Complete Guide to Pittosporum

Pittosporum is a type of flowering evergreen shrub or tree that is native to Japan, China, Australia, New Zealand and parts of Africa. Due to their popularity, pittosporums, also informally known as “cheesewoods”, are now cultivated globally and are especially popular in coastal areas and in the south of the United States. The Pittosporum genus contains about 200 different species that are part of the Pittosporaceae family.

Most varieties of pittosporum will have beautiful creamy white clusters of 5-petaled flowers. These flowers also bear a fragrant surprise: when blooming they will release a strong orange scent, which has in fact given them the nickname of “mock orange”.

In addition to its flowers, after blooming in spring, many pittosporum species bear inedible fruit that contains its seeds. These fruit capsules are often green and mature to a brownish color and divide. Once divided, its seeds will often be an attractive orange-red color and are coated by a resin-like substance. In fact, the name pittosporum is due to its seeds, as it derives from the Greek pitta, meaning “tarry”, and spermum meaning “seed”

However, the main traits for which pittosporums are chosen are their foliage and the form it takes. Their leaves are often ovate or elongated and grow alternately, with many species and varieties that have attractive white edges on their green leaves.

In fact, due to their foliage, pittosporums are one of the best and most useful plants for your garden. They are often used to create screens, hedges and barriers due to their height and wide but compact spread.

They are also quick-growing, resistant and adaptable to different growing conditions, with most being cold-hardy from USDA zones 8 to 10, being drought resistant and salt-tolerant, making it a popular choice for coastal areas as well.

Pittosporum hedges are great alternatives to loropetalum hedges, especially when to comes to windier and more saline intensive areas.

With around 200 different species contained in the Pittosporum genus, you’ll be able to find different plants for all your gardening needs. This guide will teach you about the different Pittosporum varieties that exist, how to landscape with them and how to care for them.

Pittosporum Tobira

Native to Japan and China, pittosporum tobira is one of the most popular pittosporums available. In fact, due to its popularity, the Japanese pittosporum has been selectively bred into a number of different varieties and cultivars, with variations in height, spread and foliage color.

Pittosporum tobira is also known by the names Australian laurel, Japanese pittosporum and Japanese cheesewood.

In addition to looking great, pittosporum tobira is an exceptionally resilient plant, especially compared to other pittosporum species. The Japanese pittosporum is more cold-hardy and frost-resistant and can tolerate a wider range of soils than other plants in its genus.

Height and spread

Pittosporum tobira is a broad and dense shrub that can grow from 6 to 15 feet tall and rarely it can grow even taller. Its spread is greater than its height, reaching a width of 10 to 18 feet. Its habit is clean-looking and dense, growing with a rounded form, making it perfect for hedges and screens.

This version of pittosporum can be pruned and maintained at a lower height; however, it is less tolerant to heavy pruning compared to other species of the genus. If pruned correctly, by removing the lower branches, this plant can be trained as an appealing crooked-stemmed and freestanding small tree as well.

Keep in mind that this is a versatile plant and it does well in containers and in mass plantings too.

Pittosporum tobira also grows at a very fast rate before it reaches maturity. Its growth is particularly fast until it reaches 8 to 10 feet and then begins to slow down.

Flowers and Foliage

This plant’s foliage is made of large dark green leaves that are leathery and shiny. Its leaves grow from 2 to 5 inches long and have rounded ends, which added to this pittosporum’s natural density makes for great privacy screens.

Growing on this dark green background, in spring, are clusters of 2 to 3-inch-wide creamy white flowers that grow at the branches’ tips. In addition to creating a stunning contrast between foliage and flowers, these clusters have a strong and pleasant fragrance, similar to orange blossoms.

During fall pittosporum tobira also produces small inedible green fruit capsules that eventually turn into a copper-brown color. This fruit often isn’t visible, as it is hidden in the plant’s foliage. However, once they mature and split, they reveal attractive orange-red seeds.

Varieties and Cultivars

Pittosporum tobira “Variegata”

A beautiful smaller variegated variety that grows to about 6 feet both in height and spread. Its particularity is that it has gray-green leaves with white rounded edges. In late spring it will bloom with clusters of creamy white flowers, which on the background of its particular foliage, makes for a very showy plant.

Compared to the pittosporum tobira species plant, Variegata isn’t as dense and is prone to losing leaves during winter.

Variegata is great for pruning into a small hedge but is not as effective as other varieties for privacy screening, due to its winter leaf loss. It is also a great foundation plant, especially because of its more limited size and its slower growth rate.

As with the regular tobira, Variegata is adaptable to different growing conditions, as it is cold hardy to about 5 to 10° Fahrenheit but is also drought resistant and can grow in both partial shade and full sun. In addition, as with most other pittosporums, it can be planted in coastal areas, as it tolerates salt well.

Pittosporum tobira “Wheeler’s Dwarf”

Wheeler’s dwarf, sometimes known simply as “Wheeleri” or as dwarf pittosporum is, as its name suggests, a dwarf variety that grows no more than 3 or 4 feet tall and grows from 3 to 5 feet wide.

This variety has a naturally beautiful rounded and compact mound, made up of 4-inch long dark green leaves, with no variegation. Differently from regular pittosporum tobira, this plant bears no fruit and its flowers are barely visible.

This dwarf pittosporum is an excellent selection for foreground, low boundary plantings and even small-scale groundcover. In addition, it is also a pretty addition to terraces and patios and it also looks great and grows well around swimming pools. Because of its size it can do very well in containers and pots, as well as a background for flower beds, due to its non-invasive root system.

Compared to the regular pittosporum tobira, Wheeler’s dwarf is not as sturdy and resistant: it needs excellent soil drainage and is not as cold-hardy as other varieties, as it risks being damaged at 10°F. Be aware that this variety in particular tends to do better along the coast compared to inland planting.

Pittosporum tobira “MoJo”

MoJo is another dwarf pittosporum variety that only grows up to 3 feet tall and 3 feet wide. Its foliage is lighter green variegated color and instead of white-edged leaves, they are yellow-edged. Its habit is compact, albeit less so compared to other varieties of pittosporum tobira and the plant also has a slower growth rate. Compared to Wheeler’s dwarf, during spring, MoJo has clusters of creamy-white flowers that are visible.

MoJo is indicated as a great foundation plant, for mass plantings and for elegant short rows or walkways.

Amongst the dwarf varieties, MoJo is sturdier and is resistant in more arduous climactic conditions. In fact, it is cold-hardy to USDA zones 7 – 10 and does not need as much light to thrive; so, it is sufficient to plant it either in full shade or part sun.

Pittosporum tobira “Cream de mint”

Cream de mint, also known as the pittosporum tobira “Shima”, is another dwarf variety that reaches 24 to 30 inches in height and spread. Compared to other varieties, cream de mint has a less rounded look to it, while maintaining a mounded habit that doesn’t require pruning to preserve its compact form. Its leaves are gray-green with a creamy white edging. Its flowers are also creamy white; however, they are barely visible.

This variety is best indicated as groundcover but can also be used for foundation or border plantings.

Pittosporum Tenuifolium

Native to New Zealand, pittosporum tenuifolium is also known as pittosporum nigricans or by its Maori names such as Kohuhu, Black Matipo and Tawhiwhi. Kohuhu is one of the taller pittosporums that can grow as an upright shrub or a tree. It is one of the more particular and popular pittosporums especially due to its dark flower and fruit colors and elongated leaf shape.

Pittosporum tenuifolium is not as hardy as pittosporum tobira but it can tolerate down to USDA zone 8 and is particularly suited to beach conditions.

Height and Spread

Pittosporum tenuifolium is an evergreen species that can grow more than 30 feet tall, if left unpruned. It predominantly grows much taller than it does wide, with a spread that is often half to two-thirds its height. Kohuhu has a compact habit, but it is looser than pittosporum tobira. Nonetheless, it is still a great selection for borders and hedges; it is widely used as such in New Zealand.

This species is much more tolerant of pruning compared to the Japanese pittosporum. In fact, by pruning its lower limbs, Kohuhu can be grown as a relatively tall but slender tree, as its trunk will grow to a diameter of around 1 to 1.5 feet.

Flowers and Foliage

What really stands out about pittosporum tenuifolium is its distinctive color scheme. Its silvery wavy green leaves form a stunning contrast with its blackish bark and stems. Its trunk is usually lighter and as it grows outwards, the ends of its branches become progressively darker.

The species name, tenuifolium, describes the shape of its leaves: in Latin, tenui means “thin”, while folium means “leaf”. In fact, Kohuhu’s leaves grow to 1 to 2.5 inches long, and are half as wide, usually with an oblong to round shape. These leaves tend to have a shiny appearance and a smooth texture, especially as they age.

Kohuhu’s flowers are particularly beautiful; they grow in small, half-inch dark purple clusters that blossom in spring. Their fragrance, which is particularly noticeable at night, is honey scented. Unfortunately, these clusters of flowers aren’t always visible because they grow as axillary buds, between its branches and leaves.

After blooming, this plant also produces round-shaped fruit, about half an inch in diameter, which is initially green, but then ripens to black and divides in two or three segments. When the fruit opens, it reveals intensely black seeds that are coated in a sticky substance.

Varieties and Cultivars

Pittosporum tenuifolium “Silver Sheen”

Without doubt the most cultivated of pittosporum tenuifolium is Silver Sheen. Compared to the species plant, Silver Sheen has much smaller leaves and a more open habit. The beauty of this variety is that its black branches are more visible due to its smaller leaves. In addition, its light green silvery leaves provide an absolutely stunning contrast to its branches. This is especially true when the sun is shining, accentuating its natural silver glimmer.

Silver Sheen’s growth is similar in height and width to the standard pittosporum tenuifolium and it responds very well to shearing, making it an excellent selection to grow as a tree as well as for hedges and borders. Compared to other pittosporum hedges and borders, Silver Sheen is great for privacy but doesn’t block out as much light, due to its more open habit. 

Pittosporum tenuifolium “Garnettii”

Garnettii is an award-winning variegated form of pittosporum tenuifolium: its gray-green leaves have irregular white edges with spots of light red or pink that usually emerge during winter. Compared to Silver Sheen, Garnettii has a more compact habit, so it is particularly good for privacy screens. Due to its variegated leaves, it will also provide a touch more color to your garden, even if its dark branches are slightly less visible.

Its blooming period is slightly later than your average Kohuhu, as it begins blossom in late spring to early summer.

Garnettii is also more frost-resistant than other pittosporums, but it will still struggle under more extreme freezing conditions.

Pittosporum tenuifolium “Marjorie Channon”

Marjorie Channon is a more compact and variegated version of pittosporum tenuifolium. While maintaining an upright growth, this evergreen shrub tends to grow 8 to 12 feet in height and 6 to 8 feet in width. It has a much more rounded and pyramid shaped habit compared to its species plant, giving it a “bushier” feeling. Due to these features, it works well as an individual plant or when grown in a pot but can also be used as a shorter hedge or border, thanks to its dense habit.

Marjorie Channon’s leaves tend to be smaller than the traditional Kohuhu, but they remain round shaped to ovate. Its foliage is a gray-green color with quite neat white edges. Its flowers tend toward a blackish-red color and they tend to bloom in early summer.

Pittosporum tenuifolium “Silver Queen”

Silver Queen is another award-winning Kohuhu plant that is particularly beautiful. While still growing rather tall, to around 10 to 12 feet, this plant is much more compact and denser compared to other pittosporum tenuifoliums. This version has a spread of 6 to 8 feet and is composed of gray-green leaves with somewhat uniform white edges. One of its particularities is that its foliage acquires tinges of pink during winter, for some extra color. While its dark purple flowers are small and barely visible, Silver Queen will give off a strong honey fragrance.

While this pittosporum has a naturally elegant rounded form, it also responds well to pruning, making it an excellent choice for hedges and borders of different sizes.

Pittosporum tenuifolium “Golf Ball”

The Golf Ball, as revealed by its name, is a pittosporum tenuifolium cultivar that has an extremely round habit, that resembles a large ball. The plant only grows to about 30 inches both in height and in width, but it maintains its round shape with minimum to no pruning.

Its foliage is a minty green color, with dark purple flowers that grow during late spring to early summer but are nearly imperceptible.

This plant is an excellent choice for short round hedges or as a potted plant. It has a naturally elegant quality to it, for a classy look to your garden.

Pittosporum Eugenioides

Native to New Zealand, pittosporum eugenioides, also known as lemonwood or Tarata, is one of the absolute tallest pittosporums available.

It is a lovely large evergreen shrub or tree that is another excellent hedge and is especially popular in Australia.

In some ways tarata is similar to pittosporum tenuifolium, given that both grow very tall, have elongated leaves and a similar habit. However, there are relevant differences, including foliage, twig and flower color.

The name species name, “eugenioides” is given by its similarity to the Eugenia genus, of the myrtle family.

Height and Spread

Pittosporum eugenioides can grow up to 40 feet tall and 15 feet wide in the wild. Its habit is rather dense and takes on a pyramid shape, especially as a young plant. When it begins to age, however, lemonwood will begin to branch out, opening up its habit and becoming more rounded and spreading in shape.

If left unpruned, Pittosporum eugenioides has a beautiful shape that is wild yet contained. Nonetheless it is often found as a hedge or border because it tolerates pruning extremely well. It can also be grown as a beautiful free-standing shade tree.

This plant is also rather fast growing, with the ability to grow a couple of feet per year.

Flowers and Foliage

Lemonwood’s dense foliage is made up of yellowish-green leaves that, somewhat unsurprisingly, emit a very pleasant strong lemon aroma, especially when crushed. Its leaves range from oblong to elliptical and can grow 2 to 4 inches long, with characteristic wavy edges and are moderately glossy. Its leaves may sometimes grow with a slightly darker green tone, depending on its environment.

During spring, Pittosporum eugenioides grows clusters of small half-inch yellow flowers that are also strongly fragrant, after which clusters of oval green fruit grow, containing its black seeds, that persist through fall and winter.

Of particular note is its beautiful smooth trunk that is a grayish-white color and tends to curve under a lush foliage canopy.

Varieties and Cultivars

Pittosporum eugenioides “Variegatum”

Tarata Variegatum, or variegated tarata, is an award-winning variety of Pittosporum Eugenioides. The main difference between this variety and the standard tarata is that the foliage here has attractive creamy white edges to its pale green leaves.

Its flowers are also slightly different, with its clusters that are a pale yellow to nearly greenish color that are more visible than the standard tarata. 

Pittosporum Undulatum

Native to Australia, Pittosporum Undulatum is also known as Victorian box, Australian cheesewood, native daphne and mock orange. Victorian box is a tree-form of pittosporum that is fast-growing and can be an invasive plant.

This plant’s main particularity is that it abundantly grows yellowish-orange fruit, from which it derives the name mock orange.

It is particularly suited as a background plant or a yard tree due to its beauty. It can also be grown in a large container, although as it ages its strong roots can become invasive.

Height and Spread

Pittosporum Undulatum can reach heights of 40 feet; it grows quickly to 15 feet, after which its growth rate slows.

It can grow as a single or multi-stemmed trunk, with a dense and elegant dome-shaped habit that contributes to its majestic beauty.

This tree tends to have an equal spread to its height but responds very well to pruning.

However, the main issue with this tree is that when its fruit ripens and opens, sticky golden orange seeds will fall to the ground, making for a messy lawn or pavement.

Flowers and Foliage

Australian cheesewood has long medium to dark green glossy and wavy leaves that grow from 4 to 6 inches long. The species name of “undulatum” is given by the undulating or wavy quality of the leaves’ edges.

In early spring, this pittosporum will yield small creamy white to yellowish clusters of flowers that are about half an inch in diameter. These flowers have a strong daphne-like perfume, from which the plant derives another of its names, native daphne.

After flowering, the tree will develop its yellow-orange fruit, which tends to attract birds that will disperse the seeds.

Pittosporum Crassifolium

Native to New Zealand, Pittosporum Crassifolium is an evergreen shrub or small tree that is also commonly known as karo, stiffleaf cheesewood or seaside pittosporum.

This pittosporum is slightly different than the others due to its maroon colored flowers, making it quite attractive.

Karo can be used as a screen or a hedge but is also beautiful when grown as a tree.

This plant is also notably wind-resistant and tolerates salty ocean winds as well.

The downside of this plant is that birds easily spread karo seeds, making this plant somewhat invasive.

Height and Spread

Karo usually grows to around 15 feet tall, but in the wild they can even grow to 25 feet within 8 to 10 years. Its spread usually amounts to about half of its height.

This plant usually grows with a compact low canopy that takes on a rounded shape.

If grown as a tree, Karo can be grown with a similar shape to Pittosporum Undulatum, so to maintain its compactness and density.

Flowers and Foliage

Pittosporum Crassifolium has leathery, oval-shaped gray-green to deep green leaves. Its obovate leaves grow 1 to 2 inches long and have rounded ends. The top parts of its leaves are shiny while the bottom have a velvety texture

Karo’s flowers are small but very showy. They grow in terminal clusters of quarter inch flowers that are maroon colored and grow in early spring. These star-shaped flowers contrast beautifully with the plant’s grayish green leaves.

After blooming, Pittosporum Crassifolium develops a fleshy greenish fruit that bears its seeds.

Varieties and Cultivars

Pittosporum crassifolium “Compactum”

Pittosporum Crassifolium Compactum or “nana” is a dwarf version of this pittosporum that only grows to about 3 feet tall and 3 to 5 feet wide.

The compactum or nana is essentially only a dwarf variation of Pittosporum Crassifolium that is especially dense, with no other relevant differences compared to the species plant.

Compactum is a great choice for groundcover, foundation planting or for small borders with a touch of showy color.

Pittosporum crassifolium “Variegatum”

This variegated Pittosporum Crassifolium has gray to bright green leaves that present irregular creamy white edges. This version is particularly beautiful, especially when it is in bloom with its maroon flowers, as they contrast well with the plant’s striking foliage.

Variegatum is also significantly smaller than the standard Pittosporum Crassifolium, as it only grows 6 to 8 feet tall, with equal spread if not slightly smaller spread.

This plant can be used for hedges and borders but with pruning can also be grown as an elegant small tree.

How to care for Pittosporum

Pittosporums are generally low-maintenance plants that are resilient in different growing conditions and are easy to cultivate.

Climate

Pittosporums are plants that thrive in mildly warm but not excessively hot climates. Most pittosporum species are perfect for coastal areas due to their salt tolerance. In addition, these plants are resistant to windy conditions.

While most cheesewood species are cold hardy to USDA zones 8 to 11, they are not frost-resistant. In addition, whilst pittosporums are strongly wind-resistant, they do not fare well in subfreezing winds. So, in especially cold and windy areas it is best to plant your pittosporum in a container that can be moved either indoors or shielded from subfreezing winds.

Light

Pittosporums thrive in full sun to part shade and are known not to be picky with regards to lighting and general growing conditions.

However, these specifications vary depending on the climate of the area: if you live in particularly hot zone, it is best to plant your pittosporum in partial shade, making sure that it avoids direct sunlight in the warmest afternoon hours.

Watering

Pittosporum plants grow best when they receive regular water, but you should be extremely careful not to drown the plant, as it can be prone to root rot and fungal diseases.

Sufficient watering is fundamental especially when your pittosporum is establishing itself, so water at least once every 5 to 7 days. Once established, slightly decrease watering frequency to once a week. During winter, further decrease watering to once every 9 or 10 days.

Remember to water at the base of the plant, directly on the soil, to avoid damaging the plant’s foliage.

Pittosporums are also known to be moderately drought tolerant plants.

Soil

This versatile plant tolerates a range of soil conditions, including neutral and even slightly alkaline soils but it will thrive in slightly acidic soil with a pH of 5 to 7.

If your soil is overly alkaline, however, it can lead to magnesium deficiency, so avoid using lime or other agents that will increase soil pH.

A necessary condition to healthy pittosporum growth is that the soil is well-drained. If its soil is not sufficiently drained and retains excessive moisture your pittosporum will risk root rot.

While pittosporums can grow in a range of different soils, if you do decide to treat your soil, your best choice is to use a perlite and peat moss mixture.

Fertilizer

Fertilize pittosporums once each spring, before new growth with a nitrogenous or an all-purpose slow-release fertilizer.

Since there is a risk of damaging your pittosporum if it is overfertilized, an NPK 8-8-8 fertilizer is best indicated.

Adding organic mulch during hotter periods is useful, as it will help your plant retain moisture. 

Planting

Plant your pittosporums in spring or fall.

Avoid planting then in full sun in extremely hot areas and plant them in a shielded area from freezing wind in cold and windy zones.

In addition, be careful not to plant them in poorly drained areas where rain will accumulate, otherwise they will develop root rot.

When mass planting pittosporums, keep your specimens at least 6 to 8 feet apart for hedges and privacy screens, while if you are planting them as border plants leave a couple of extra feet of between plants.

Pruning

Pittosporums respond very well to pruning and training.

Most species of pittosporum can be trained to grow as trees by pruning their lower branches.

Pittosporums also respond well to trimming, so their size can be easily contained with proper care.

However, keep in mind that frequent pruning can hinder flower growth, so if you wish to maintain a greater flower output, prune only when necessary.

In addition, prune pittosporums only after the plant has already finished its blooming period, otherwise it may compromise the following year’s flower growth.

Propagation

Pittosporums can be propagated from seed, which is contained in the fruit that grows after its flowers have finished blooming.

Alternatively, pittosporums are easily propagated by taking semi-hardwood cuttings during summertime and planting them in peat moss and perlite mix. To aid growth, keep the soil moist and maintain high humidity. 

Diseases and parasites

The main problems that pittosporum can encounter is infestation by aphids and scale pests, particularly pink wax scale, white wax scale and mealy scale. The clearest manifestation of these pests is if your pittosporum leaves develop a black sooty covering, which is when mold grows on insects’ honeydew secretions.

To get rid of these infestations, the most effective method is to apply horticultural oil to the plant’s leaves.

Leaf spots may also develop if you water your pittosporums directly on their leaves.

Sometimes pittosporums develop yellow leaves; this is usually due to chlorosis, because chlorophyll is lacking. Often chlorosis and yellowing leaves are caused by a lack of magnesium, which in turn is due to an excessively alkaline soil and can be solved by amending the soil.

When pittosporums are overwatered, they are at a severe risk of irreparable root rot.

Pittosporums can also be susceptible to fungal diseases as well.

Most species of pittosporum are also deer resistant.

Published by Davide Zancan on 4 Novembre 2020