Living Walls™ are generally straightforward to care for, and most pest or disease problems are easier to manage when spotted early. An occasional look through your hedge and nearby planting is usually enough to notice pests, unusual leaf damage or changes in vigour before they become serious.
Good watering, feeding, drainage, trimming and general care help keep your hedge healthy and resilient. As with any garden plant, occasional pests or disease can still occur, and light damage is often cosmetic rather than a threat to the hedge.
If something does not look right, first consider whether it may be related to watering, drainage, weather, nutrition or normal leaf replacement before assuming it is a pest or disease.
For routine hedge care, see our Care & Maintenance guide.
Look occasionally for unusual leaf damage, sticky foliage, insects, webbing, dieback or changes in colour or growth. It is also worth checking nearby planting, as some pests move readily between different plants.
You do not need to inspect your hedge constantly. The aim is simply to notice unusual changes early, when most problems are easier to manage.
What to look for: Older leaves turning a clear or bright yellow before dropping, while newer foliage remains healthy and the hedge continues to grow normally.
Why it happens: Evergreen does not mean every leaf remains on the plant indefinitely. Older leaves are naturally replaced, and some hedge varieties do this more noticeably at particular times of year.
What to do: Usually nothing. If the yellowing is mainly confined to older leaves and the rest of the hedge looks healthy, it is generally part of the normal leaf-replacement cycle.
What to look for: More leaf drop than usual, thinning foliage or bare patches.
What it can mean: Some leaf drop is normal as older leaves are replaced. More noticeable leaf drop can also follow drought, overwatering, root disturbance, cold, wind, nutrient stress or pest and disease pressure.
What to do: Check soil moisture, drainage, irrigation and recent weather first. Look through the foliage for pests or other obvious damage. If the hedge is otherwise healthy and producing normal new growth, some temporary leaf drop may not be a concern.
What to look for: Foliage becoming pale, yellow-green or generally less vibrant than normal.
What it can mean: Poor colour can result from too much or too little water, low nutrients, root stress, poor drainage, seasonal conditions or pest activity. The pattern can be useful, for example whether the whole hedge is affected, only new growth, or just one section.
What to do: Check watering and drainage first. Consider whether the hedge is due for feeding, and look for pests if the yellowing is patchy or accompanied by sticky foliage, distortion or other leaf damage.
Healthy new growth is usually a better indication that conditions have improved than whether older discoloured leaves regain their original colour.
Hot, dry or windy conditions, frost, sudden temperature changes and competition from established tree roots can all affect hedge foliage. Damage may appear as browning, scorching, leaf drop or reduced growth.
Check recent weather, soil moisture, drainage and irrigation before assuming a pest or disease is responsible.
Not every insect needs treating. Light populations are often tolerated by a healthy hedge and may be kept in check by insect-eating birds, ladybirds, predatory insects and mites, and parasitic wasps.
If treatment is needed, identify the pest first. Different products work in different ways. Contact treatments need to reach the pest directly, while systemic insecticides are absorbed by the plant and can control insects feeding on it. Horticultural oils and other lower-impact treatments may also be useful for some pests.
For minor or uncertain problems, your local garden supply retailer can help identify suitable products. Kiwicare and Yates also publish useful New Zealand pest and disease information online.
Always check that a product is suitable for the pest and plant concerned and follow the current label directions. Some products can also affect beneficial insects, mites or pollinators, so avoid unnecessary spraying.
For significant infestations, recurring problems or serious dieback, consider using a professional gardener, arborist or spray contractor.
What to look for: Clusters of small, soft-bodied insects on new shoots, buds or the undersides of leaves. New growth may curl or distort. Sticky honeydew, ants or black sooty mould can also indicate aphids.
Why it matters: Small numbers are usually manageable, but aphids can multiply quickly and heavy infestations can distort or weaken new growth.
What to do: Check soft new growth regularly. Small infestations may be removed with water or by trimming badly affected shoots. Natural predators such as ladybirds and parasitic wasps often help control them. If numbers continue to build, use a suitable treatment for aphids.
What happens to damaged foliage: Badly curled or distorted leaves may not return to their original appearance. Once aphids are controlled, healthy new growth should gradually restore the appearance of the hedge.
Reducing the risk: Avoid excessive nitrogen feeding and monitor soft new growth during spring and summer.
What to look for: Small brown, black, grey, white or waxy bumps attached to leaves and stems. Leaves may yellow, and sticky honeydew, ants or black sooty mould may also be present.
Why it matters: Light infestations may cause little damage, but heavy scale infestations can weaken the hedge and reduce vigour.
What to do: Small infestations can be removed by hand or badly affected growth can be pruned out. Horticultural oils may be useful where good coverage is achieved. More significant infestations may require a suitable systemic insecticide.
Dead scale can remain attached to the plant for some time, so check whether insects are still alive before assuming treatment has failed.
What happens to damaged foliage: Yellowed or badly marked foliage may remain unattractive for a while. Healthy new growth should gradually improve the appearance once the scale is under control.
Reducing the risk: Check stems and the undersides of leaves occasionally. Ant activity, sticky honeydew or the first appearance of sooty mould can be useful early warning signs.
What to look for: A black or dark grey, soot-like coating on leaves and stems. Foliage may also feel sticky, and ants are often present.
Why it happens: Sooty mould grows on the honeydew produced by sap-sucking insects such as scale, aphids, mealybugs and passionvine hoppers. The mould itself is usually secondary to the insect infestation.
Why it matters: Light sooty mould is mainly cosmetic. A heavy coating can reduce the amount of light reaching the leaves, but the underlying insect infestation is usually the more important problem.
What to do: Find and control the insect producing the honeydew first. Once the source is controlled, the mould will gradually weather or wash away. Accessible foliage can be wiped or washed if appearance is important.
Reducing the risk: Watch for honeydew, ants and sap-sucking insects before sooty mould becomes widespread.
What to look for: Small white or grey insects with a cottony or waxy coating, usually clustered around leaf joints, stems or the undersides of leaves. Honeydew, ants and sooty mould may also be present.
Why it matters: Light infestations are generally manageable. Larger populations can weaken new growth and reduce hedge vigour and appearance.
What to do: Remove small infestations by hand or prune out badly affected growth where practical. Horticultural oils may help where good coverage is achieved. Significant infestations may require a suitable insecticide.
What happens to damaged foliage: Yellowed or badly marked foliage may remain discoloured, but healthy new growth should gradually improve the appearance once the infestation is controlled.
Reducing the risk: Look around leaf joints and sheltered parts of the hedge during active growth. Ant activity or sooty mould can provide an early clue.
What to look for: Silvery or pale mottling on leaves, sometimes with twisting or distortion of new growth. Tiny dark specks may also be visible. Thrips often build up in warm, dry, sheltered conditions.
Why it matters: Light infestations are usually cosmetic. Heavier or persistent infestations can leave foliage dull or distorted and may reduce vigour.
What to do: Check both sides of affected leaves, especially new growth. Light infestations may not require treatment. If numbers are increasing or damage is significant, use a suitable treatment for thrips. Good coverage is important with contact sprays, particularly on the undersides of leaves.
What happens to damaged foliage: Thrips-damaged leaves will not return to their original appearance. Once the pest is controlled, healthy new growth will gradually replace or cover the damaged foliage. Badly affected leaves can be trimmed off if appearance is important.
Reducing the risk: Keep hedges adequately watered through hot, dry weather and monitor susceptible plants in warm, sheltered positions.
What to look for: Fine yellow or pale speckling, bronzing or dull foliage, sometimes with very fine webbing. Mites are tiny and often easiest to find on the undersides of leaves.
Why it matters: Light infestations are largely cosmetic. Heavy infestations can cause significant bronzing, leaf damage and reduced vigour. Populations can increase quickly in hot, dry weather.
What to do: Check the undersides of affected leaves. Horticultural oils may help with light infestations. Significant infestations may require a suitable miticide. Avoid unnecessary broad-spectrum spraying because beneficial predatory mites can help control pest populations.
What happens to damaged foliage: Heavily speckled or bronzed leaves may remain marked. Healthy new foliage should improve the hedge’s appearance once the mites are controlled.
Reducing the risk: Monitor during hot, dry weather and keep the hedge adequately watered.
What to look for: Small jumping insects on shoots and stems. Juveniles have distinctive white, fluffy-looking tails, while adults have mottled, semi-transparent wings. Honeydew, ants and sooty mould may also appear.
Why it matters: Light populations may cause little damage, but large populations can reduce plant vigour and contribute to wilting, leaf drop or dieback, particularly where plants are already under stress.
What to do: Monitor from spring when juveniles begin appearing. Natural predators can help. Where practical, remove heavily infested surrounding vegetation or stems carrying egg-laying sites. If numbers become significant, use a suitable treatment for passionvine hoppers.
Reducing the risk: Check nearby planting as well as the hedge because passionvine hoppers can move into the hedge from other host plants.
What to look for: Holes, chewed leaves, scalloped edges or sections of foliage eaten away. Caterpillars or beetles may be visible among the foliage.
Why it matters: Light feeding is usually cosmetic and healthy hedges can tolerate some damage. Heavy infestations can strip new growth and affect hedge density or appearance.
What to do: Remove caterpillars or beetles by hand where practical. Encourage insect-eating birds and beneficial insects, and avoid unnecessary broad-spectrum spraying. If damage becomes significant, identify the pest before choosing a treatment.
What happens to damaged foliage: Chewed leaves will remain marked, but healthy new growth will usually cover or replace the damage over time.
Reducing the risk: Diverse planting nearby can support insect-eating birds and beneficial insects that provide natural pest control.
What to look for: Localised wilting or sudden dieback of individual branches, together with small round holes in stems or branches. Sawdust-like material may be visible around an active hole.
Why it matters: Lemon tree borer larvae tunnel inside living wood. Significant damage can weaken branches, cause dieback or, where major stems are affected, threaten the plant.
What to do: Prune out badly damaged or dying branches where practical. An active larva can sometimes be killed by inserting fine wire into the tunnel, and specialist borer treatments are available for active holes. Follow the current product directions.
Reducing the risk: Avoid unnecessary damage to woody stems and branches and monitor pruning wounds where lemon tree borer is known to be present.
What to look for: Blistering, dimpling or small raised lumps on new leaves, often with tiny insects or juvenile stages on the undersides. Psyllid damage is most noticeable on fresh spring and summer growth and can affect susceptible plants including Syzygium and some Pittosporum.
Why it matters: Light infestations are usually cosmetic. Heavy or repeated infestations can distort new growth, reduce the appearance of the hedge and, if severe, affect vigour.
What to do: Check whether psyllids are still active before treating, as old damage can remain after the insects have gone. Significant active infestations may require a suitable systemic insecticide or horticultural oil. Trim out badly distorted growth once the infestation is controlled if appearance is important.
What happens to damaged foliage: Psyllid-damaged leaves will not return to their original shape. Once the infestation is controlled, healthy new growth will gradually replace or cover the damaged foliage.
Reducing the risk: Monitor soft new growth during spring and summer so significant infestations can be dealt with before they build.
What to look for: Brown, black, tan or reddish spots on leaves, sometimes with yellowing around the edges. Spots may remain small and scattered or enlarge and merge. Older affected leaves may eventually drop.
Why it matters: A small amount of leaf spotting is often cosmetic, particularly following wet or humid weather. More widespread or recurring spotting can indicate a fungal or bacterial leaf disease and may reduce foliage density if significant leaf drop occurs.
What to do: Remove badly affected or fallen leaves where practical. Improve airflow through and around the hedge with appropriate trimming. Direct irrigation at the root zone rather than repeatedly wetting foliage, and check that the hedge is not being overwatered. If spotting continues to spread or causes significant leaf loss, identify the likely cause before choosing a treatment.
What happens to damaged foliage: Existing spots will remain visible. Healthy new growth should gradually restore the appearance once the underlying problem is controlled.
Reducing the risk: Maintain good drainage and airflow and avoid unnecessary wetting of foliage.
What to look for: Wilting, yellowing, poor growth or dieback that cannot be explained by lack of water. Leaves may remain dull or droop even when the soil is wet. In advanced cases, roots may be brown or black and soft rather than firm, and darkened tissue can sometimes appear around the base of the stem.
Why it matters: Root diseases such as Phytophthora and Pythium can be serious. They damage the root system and interfere with the plant’s ability to take up water and nutrients. Severe cases can kill individual plants or sections of hedge.
What to do: Check soil moisture and drainage first. Correct drainage problems and avoid unnecessary watering. Where treatment is appropriate, phosphonate or phosphorous-acid products are available for some root diseases. Use a suitable product and follow the current label directions. Severely affected plants may not recover.
Reducing the risk: Good drainage is the most important preventative measure. Some hedge species are more susceptible to root disease, including New Zealand natives such as Griselinia, Corokia and Olearia. In known wet or waterlogged areas, improve the drainage first and consider raising the rootball as set out in our In-Ground Installation Guide. Where the site remains unsuitable, choose a more tolerant hedge variety instead.
For more information, see our How to Improve Drainage guide.
What to look for: Bright yellow or orange-yellow powdery spots on soft new growth, sometimes with distorted leaves, damaged shoots or shoot-tip dieback. Myrtle rust affects plants in the myrtle family.
Why it matters: Myrtle rust can seriously damage susceptible plants, particularly repeated soft new growth.
What to do:
Reducing the risk: Maintain good airflow around susceptible plants and check soft new growth regularly during warm, humid weather.
Note: Twining Valley Nurseries no longer grows the susceptible Syzygium australe varieties that were previously part of the Living Walls™ range.
If a problem is spreading quickly, causing significant dieback, affecting several hedge lengths, or you cannot confidently identify the cause, consider asking your landscaper, professional gardener, arborist or spray contractor for advice.
Professional help is also a good option if you would prefer someone else to identify and treat the problem for you.
Your local garden supply retailer can help with treatment options, and the Kiwicare and Yates websites provide useful New Zealand pest and disease information.
