Pittosporum

( pit - toss - POOR - um )

At-A-Glance Information

This popular genus of evergreen shrubs and trees commonly called Cheesewood needs full sun or partial shade and moderate to regular water, though this varies somewhat by species. They are grown for their handsome foliage and neat form, and produce sweetly fragrant clusters of flowers followed by berries. Beautiful when allowed to branch naturally. Take care when choosing a spot to plant these shrubs, as the fruit produced can be a nuisance after falling to the ground; the seeds inside are sticky and can make a mess of walkways. Pittosporum is great as a windbreak or screening hedge.

Pittosporum Species and Varietals

The genus Pittosporum includes somewhere around 200 species, and is a member of the plant family Pittosporaceae. The best growing zones for Pittosporum vary depending on the species. For more information, see the descriptions below. To find your zone, click here: Zone Map.

​Pittosporum crassifolium (Karo)
This species grows well in zones 9, 14-17 and 19-24 and is native to New Zealand. It can reach 25 feet tall and 12 feet wide, but with hard pruning can be kept to 6-10 feet tall and 6-8 feet wide. Leaves are greyish green and flowers are small and maroon, appearing in late springtime. Can take seaside conditions and some drought. Choice varieties include 'Compactum' (pictured; 2-4 feet tall and 4-6 feet wide) and 'Variegatum' (reaches 8 feet tall and wide, with creamy-white edged leaves, this variety is best in part shade in areas that get hot summer weather).

Pittosporum eugenoides (Lemon Wood)
This species is best in zones 9, 14-17, 19-22, H1 and H2 and is native to New Zealand. It can be grown as a tall hedge, or trimmed into a tree; usually reaches 20-40 feet tall and 6-15 feet wide. Leaves are green to yellow-green and wavy. Flowers are yellow and fragrant, blooming in springtime. Variety 'Mini Green' reaches just 6 feet tall and 4 feet wide, with emerald green foliage. Another choice is 'Platinum', with grey-green leaves edged with cream, reaching 8-10 feet tall. 'Platinum' needs some shade to perform at its best.

Pittosporum phillyreoides (Pittosporum angustifolium) (Desert Willow)
This species is native to Australia, growing well in zones 8, 9 and 12-24. It slowly reaches 20-25 feet tall and 10-15 feet wide. This weeping tree has dark green narrow leaves and blooms in late winter to early springtime. Flowers are yellow, followed by yellow fruit. Great near patios. Can tolerate heat and aridity and has naturalized itself in some desert areas.

Pittosporum rhombifolium (Queensland Pittosporum)
This species is best in zones 12-24, H1 and H2, and is native to Australia. Slow grower to 15-35 feet tall and 12-25 feet wide. Leaves are green, glossy and diamond-shaped. White flowers bloom profusely in late spring and are followed by yellow-orange fruits that stay on the plant from fall through winter. Great as a lawn tree or patio, and can also be planted as a screening plant. This species is resistant to Oak Root Fungus.
Pittosporum tenuifolium (Kohuhu)
This New Zealand native plant grows well in zones 9, 14-17 and 19-24. It grows quickly to 15-25 feet tall and 10-15 feet wide, with deep green leaves and purple flowers. Choice varieties are listed and described below.
'Abbotsbury Gold'
With yellow-green leaves that have dark green edges.
'Silver Sheen'
Open habit shrub with silvery, sparkly green leaves.
'Wrinkled Blue'
With wrinkled leaves that are silvery blue. Reaches 12 feet tall and 6 feet wide.
'Marjorie Channon'
8-10 feet tall and almost as wide, with light green leaves outlined in creamy white.
'Purpureum'
Leaves emerge green and mature to bronze-purple.
'Golf Ball'
Compact variety, reaches 3-5 feet tall and wide. Great as a low hedge.
'Tom Thumb'
3 feet high and 2 feet wide, with green leaves that mature to bronze-purple. Great in pots.
Pittosporum tobira (Tobira, Japanese Mock Orange)
This species grows well in zones 8-24, H1 and H2. It is native to Japan, and has a dense habit, reaching 6-15 feet tall and as wide. Older plants can be trimmed into trees, or kept as a shrub. Leaves are leathery, shiny and dark green, and flowers are creamy white and mimic the smell of orange blossoms. This species is tolerant of seaside conditions. Choice garden varieties are listed and described below.
'Variegatum'
5-10 feet tall and wide, with smaller leaves than the species that are grey-green with a creamy white margin. 
'Wheeler's Dwarf'
2-3 feet tall and 4-5 feet wide, this dwarf selection has dark green, leathery leaves and is a choice plant for foregrounds, boundaries, or even as a small-scale groundcover plant.
'Turner's Variegated Dwarf'
Leaves are grey-green with creamy white margins, on a plant that tops out at 2-3 feet tall and 4-5 feet wide.
'Cream de Mint'
2-2.5 feet tall and wide, with mint-green colored leaves that have creamy white borders.

​Pittosporum undulatum (Victorian Box)
This species grows well in zones 14-17, 21-24, H1 and H2 and is native to Australia. It quickly reaches 15 feet tall, then slowly grows to top out at 30-40 feet tall and just as wide. It takes the form of a single or multi-trunked tree with a dome-shaped canopy. Leaves are glossy green and wavy-edged and flowers are creamy white and very fragrant, blooming in springtime. Can be kept as a screening hedge if plants are spaced about 5-8 feet apart and kept sheared around 10-15 feet tall. Roots of this species are strong, and mature tree roots are considered to be invasive.

Caring for and pruning pittosporum shrubs

Caring for Pittosporum plants begins with placement. These shrubs typically do best in full to partial sunlight, but can tolerate some shade. In sun, they will produce more attractive foliage and flower more profusely. Well-draining soil is essential. Pittosporum shrubs grow well in slightly acidic to slightly alkaline soil (with a pH of between 6.0 and 6.5 ideally). Water regularly when plants are establishing themselves in the garden. Once mature, these shrubs are considered drought-tolerant, though they will still benefit from occasional deep waterings, especially during dry periods. Apply mulch around the base of the plant to increase soil moisture retention. Although fertilizing is not generally required for these shrubs, they may benefit from a yearly application of a balanced, slow-release fertilizer in springtime. This will support the new growth for the year.

Pittosporum needs to be pruned only periodically to improve appearance and thin out weak branches and wayward shoots. They can be pruned for shape and size in wintertime or early springtime before new growth begins for the year. As with all plants, remove dead, damaged, or diseased areas. Aggressive pruning is not recommended for these plants, as they do not always react well. Pittosporums can be grown either in ground or in containers. If growing in a container, ensure great drainage, and water more regularly.

Propagation

​Pittosporum can be propagated either by using cuttings or from seed. To ensure that your propagated plant will have the exact same qualities and characteristics as the parent plant, use the cutting method. If you would like to experiment and see what plant you can grow from seed, just keep in mind that it will not necessarily be the same as the parent plant. To propagate your shrub, follow the instructions below:

Propagating Pittosporum by Cutting
  1. Gather your materials. You'll need a clean, sanitized, sharp pair of garden shears, rooting hormone, a pencil, and a 3-inch pot filled with well-draining compost or other organic material. If you don't have any potting medium on hand, you can make some. Just mix together equal parts (by volume) moss peat and horticultural-grade sand or grit sand.
  2. In mid- to late summer, choose the plant that you'd like to propagate. Ensure that this plant has had a good watering the night before, as this will improve the chances your cutting will take root. Cut one or more 6 inch semi-ripe portion(s) of the end of a non-blooming branch and strip the leaves off of the lower half. Make a hole in your planting medium by pushing your pencil into the soil. Dip the end of the stem in rooting hormone, and plant it in your pot. Fill in soil around the cutting to support it, but do not pack it down too much.
  3. Moisten with water, and ensure that the pot has good drainage. Your pot should be kept in warm, sunny conditions indoors (and not in direct sunlight). Water whenever your soil is dry under the top layer. After about four to six weeks have passed, your cutting should be rooted. When you notice new growth, you'll know you have roots.
  4. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring, when you can transplant it to its new home. Ensure that the last frost of the year has occurred before doing this, as it can seriously damage your new shrub.

Propagating Pittosporum by Seed
  1. Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. If you don't have any potting medium on hand, you can make some. Just mix together equal parts (by volume) moss peat and horticultural-grade sand or grit sand. You will also, after a few weeks, need individual 3-inch pots for each seedling that grows.
  2. Harvest your seeds in late summertime or early fall. The seed pods are pretty easy to spot, they're large and left on the branches after flowers have faded. Once they have dried out and begun to split open, you can harvest the seeds inside. Cut them off of the plant, placing them in a paper bag. Harvest as many as you can, and place the paper bag in a dry, cool, dark area. They will begin to split open and release the seeds contained inside. Once they have been released, take them out of the bag and put them in a container so you can work with them.
  3. Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes 8-12 weeks from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
  4. Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.
Pittosporum fruits will split open and release seeds when they are ready to be harvested.
Pittosporum seeds are covered with a sticky substance that will stick to passing animals' bodies and be transported away from the shrub.

Problems and Pests

Pittosporum shrubs suffer from the following issues:
  • Aphids
  • Scale
  • Mealybugs
  • Fungal Diseases
For more information on these issues and how to solve them, see the following links:
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Gallery

silver sheen
Pittosporum tenuifolium 'Golf Ball'
tobira variegatum

Videos

All about growing Pittosporum.
Learn about Silver Sheen Pittosporum.
Learn about Pittosporum tenuifolium.
Learn about how Pittosporums are great choices for hedges.

Resources

How to Grow and Care for Kohuhu
Pittosporum
Wikipedia: Pittosporum
The New Sunset Western Garden Book: The Ultimate Gardening Guide (2012) - Page 512, Pittosporum
If you have any questions, comments, concerns, or photos you’d like to add to the gallery, please let me know by sending me a message using the button below!
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