Pittosporum

Profile: The Pittosporum is a native shrub mainly used for hedging in New Zealand. As a bonsai, the Pittosporum has unique qualities that make it a great choice. The Pittosporum has small green leathery leaves with a slight grey underside. You may discover crimson-purple flowers from spring through to midsummer if the conditions are right. The pittosporum naturally grows into a broom-like shape. With frequent trimming, you can achieve a beautiful and ramified branch structure that mimics are a large tree. 

Tree Position: Keep this bonsai outside in a sheltered position and protected from strong winds. It may be displayed inside for up to 3 days at a time. When placed outside, place the bonsai where it will receive full sun. Keep this bonsai in part shade during hot summer days.

Watering: Pittosporums loves frequent watering on hot days. Ensure that the soil is always damp but not soaking wet. How often you water your bonsai will depend on the weather and how deep your bonsai pot is. Use your finger to check how damp the soil is before watering. If it feels a little dry, then go ahead and water. As a general rule, water every day when it's hot, and water twice a week in colder winter months. Try not to follow a schedule when watering though, instead, check the soil to see if it is wet or dry. Wait a minute or two after watering, then water again. In Japanese bonsai culture they have a saying for this; 'For bonsai, it rains two times'.

Fertilizing: Feed your Pittosporum fortnightly from spring through to autumn with a liquid fertilizer that has a balanced N.P.K ratio. Always follow the directions on the fertilizer packet, and water the bonsai thoroughly before feeding to avoid root burn. Don't feed your bonsai during winter as the soil temperature isn't high enough to trigger the bonsai's response to uptake nutrients. Do not fertilize if the tree is weak or diseased. Lastly, do not fertilize newly re-potted trees for at least a few weeks.

Re-potting: Re-pot this tree every year or two during mid-spring. The soil you use should be a well-drained soil. A basic mix consists of 1 part Dalton's coarse pumice and 1 part Dalton's potting mix. Ideally, you should use a 2 mm sieve to get most of the fine particles out. You can trim up to one-third of the roots before your bonsai goes back into the bonsai pot. Secure the tree to the pot with wire through the drainage holes. Pittosporums will benefit from extra moisture in the soil (add more potting mix to achieve this). Place the bonsai in a sheltered and slightly shaded spot for a week or two after repotting. At this crucial stage, we want to shelter the bonsai from the hot sun, heavy rain, frost, snow, and wind. Lastly, be careful to not overwater your bonsai after repotting. 

Trimming: During spring and summer, your bonsai will be in full growth. When your bonsai takes off in mid-spring, allow the tree to grow so it can gain strength. After a month or so of active growth, you can then trim your bonsai into shape. The pittosporum responds well to regular trimming (every month or so through the growing season)  Trimming frequently will make sure the bonsai doesn't have leggy or bare growth near the trunk. Try to keep the trunk and main branches free of new small growth, this will aid the appearance of an old tree. 

Trimming is done to keep unwanted growth in check, direct growth, and to develop ramified foilage.  Throughout the growing season, cut back stems to a maximum of 3 or 4 leaves. For example, if a stem has elongated too far (say it has 10 leaves), you can cut this back. Leave a minimum of 3 or 4 though. Doing this will result in dense growth. When making a cut, use sharp scissors and cut on a 45-degree angle. Aim to cut right above a leaf node. 

Pruning: This involves cutting larger branches and requires you to have a concave or branch cutter ( if you have neither, a sharp pair of secateurs will do) Trimming frequently on a pittosporum will result in very dense growth, to combat this, you'll need to cut back hard once a year. The best time to make strategic pruning cuts on a Pittpsporums is from late summer through to Autumn. Don't remove more than one-third of the tree's foliage when pruning unless the Pittosporum was vigorous in its last growing season. The overall shape you are trying to achieve is a rough triangular silhouette where the top of the tree is highest. Unsightly branches should also be removed. This includes dead branches, branches that cross over each other, and branches that hide the bottom third of the trunk. Create space so light and air can enter the tree.

Wiring: Generally not required with the pittosporum as they are naturally shaped brooms, although you can wire Pittosporum at any time of the year. (except after repotting or any other major work as this will stress the tree) Larger branches will take longer to set than smaller branches. Ensure you are using the right thickness of wire for each branch. A general rule of thumb is that you should apply wire that is roughly 1/3 the thickness of the branch you are planning to wire. Remember to check on the wire that is applied in summer as branches thicken quickly during this time and the wire may cut into the wood and leave marks. 

Pests and diseases: You may find various nonharmful insects amongst the growth if the tree is allowed to get too dense. Pittosporum can sometimes be affected by an insect called Psyllid which can make tiny holes in the leaves. Spray with insecticide to control. Dark spots may appear on the leaves of the Pittosporum when it has been a wet season. Spray with a fungicide and avoid watering the leaves so much when this does occur.

Bonsai Difficulty: ★★☆☆☆