Bugs on underside of leaves, ‘sticky’ plants.

Spray the plants in late spring/early summer with an insecticide. Soapy water can also be effective. In shadier places, after aphids have been present sooty mould can occur after, due to the honeydew the aphids secrete.

Floppy, dull brown new growth at tips. Slightly older leaves may be a dull green to brown colour also.

Heavy frosts, early autumn frost or late spring frost.

Once frost damage is obvious nothing can be done to reverse it. To avoid frost damage, trees should be planted in an area more sheltered from the hardest frosts or given protection (such as frost cloth) while getting established. If frost is an issue a few doses of Seasol seaweed tonic in the lead up to the frost can help aid the trees frost tolerance.

Natives – Fertiliser

General nutrient questions rather than symptoms.

Natives naturally grow in low‑nutrient soils and are not heavy feeders.

Use natural fertilisers such as blood and bone, compost or sheep pellets. Apply lightly to avoid burning roots.

Confusion between species.

Similar appearance but different growth habits.

Kanuka grows taller with a nicer tree form. Kanuka flowers Oct–Feb; Manuka flowers all year. Kanuka flowers are about half the size of Manuka. Manuka tolerates poorly drained soils; Kanuka does not. A fun way to remember the difference between Kanuka and Manuka is: Kanuka is kind (softer foliage) and Manuka is mean (spikier foliage).

Stress symptoms, leaf issues, blossom problems.

Wet–dry extremes. Temperature swings (30° down to 5–10°). Susceptibility to fruit‑tree diseases. Weather fluctuations during blossom.

Ensure good drainage. Avoid planting too deep (top of rootball level with ground). Treat and spray as you would fruit trees.

All Species – Shot Hole Disease

Brown spots that fall out, leaving ‘bullet holes’ in leaves.

Water sitting on foliage for long periods (overhead irrigation or wet Spring).

Avoid overhead watering; use drippers. Spray before leaf‑out to prevent infection. Disease does not kill the tree or affect growth. Spraying copper at bud break and another dose mid spring will help to alleviate shothole.

Pest or disease stress similar to other Prunus species.

Being part of the fruiting Prunus family, so susceptible to similar issues.

Winter copper & oil spray. Occasional systemic insecticide. Check for caterpillars. Soapy water can deter pests. Avoid overly damp soil. Apply general fertiliser (foliar + granular). Thrips can be an issue, extreme symptoms can show silver speckled leaves. A few doses of a systemic insecticide, spaced over a couple weeks should cure this.

Yellowing leaves and possible leaf drop in Summer.

Lack of water; Ulmus require high moisture.

Reinstate consistent watering. Trees usually recover the following season.

Browning or thinning foliage.

Running too dry while establishing (common in Thuja and other conifers).

Improve watering consistency, especially during establishment. Canker can be an issue with the cypress family, especially in the closely related Cupressocyparis varieties. Galls in the branch axis are often symptoms of canker. Cupressocyparis are more susceptible to canker when in dry conditions.Fact: Cypress species are often not recommended in dairy farming situations as they contain a toxin called, isocupressic acid. This toxin causes pregnant cows to abort its calf. A better alternative for hedging is Thuja plicata, as the Thuja species doesn’t contain isocupressic acid, however still achieves the same goal of a macrocarpa or Leylandii hedge.

Fruit Tree Spraying Programme

General disease and pest management needs.

Overwintering pests, fungal diseases, poor hygiene, incorrect timing.

Step 1: Prune out dead/diseased wood and remove mummified fruit.Step 2: Apply Lime Sulphur before new growth appears.Step 3: Three weeks later, apply copper spray before buds open.Step 4: One week later, apply spraying oil (e.g. Conqueror Oil).Step 5: Final pruning on a clear day; sterilise tools if disease is present.

Young timber trees, especially thin‑barked species such as Mahogany and Melia

Bark splitting on young stems and trunks.

Dry weather slows growth, then sudden wet or ideal conditions trigger rapid growth that splits the bark. Winter sunscald on thin‑barked or newly planted trees. Black cotton soils where bark splitting is more common. Late‑season fertiliser pushing out soft new growth that is easily damaged.

Fertilise in Spring only. Keep irrigation steady through hot, dry periods. Use timely drip irrigation to maintain even soil moisture. Protect young, thin‑barked trees from harsh winter sun where possible.

Leaves curled inward, appearing dry or stressed even when soil or pots are damp.

A natural cold‑weather response known as thermonasty (or thermonastic movement). When temperatures drop, evergreen foliage like Laurel temporarily curls or closes to protect itself. This is not a sign of dehydration or poor handling.This defensive movement helps the plant cope with winter stress by:Conserving moisture – reduced leaf surface area lowers transpiration when roots draw water slowly in cold soil.Protecting leaf pores from wind – curled leaves shield stomata from harsh, drying winter winds.Reducing sun exposure – cold disrupts normal metabolism; curling limits light absorption and prevents cell membrane damage.

No action required. This is a normal seasonal behaviour and plants will reopen their leaves as temperatures rise. Ensure consistent watering during dry spells, avoid overwatering in cold periods, and allow the plants to settle. Once conditions warm, foliage will return to its usual open form and growth will continue as normal.

Foliage turning copper, bronze or rusted in Winter.

Normal photoprotective Winter acclimation. Thuja and other conifers develop a copper or metallic bronze tone in cold weather as part of a natural defence response. When Winter sunlight hits foliage that is too cold to process the energy, the plant protects itself by producing specialised pigments. In conifers, this includes the rare carotenoid rhodoxanthin, which creates the distinctive coppery colour.This phenomenon is not exclusive to conifers. Many broadleaf evergreens also change colour in Winter for the same biochemical reason — they flush their leaves with anthocyanins, producing red, burgundy or purple tones. Common examples include:Buxus (Boxwood): Orange‑bronze or olive tones in severe coldBergenia: Deep plum‑purple or ruby‑red Winter foliageNandina domestica: Crimson Winter colour intensificationAloe arborescens: Some succulents accumulate protective pigments under cold stressAcross both conifers and broadleaf evergreens, this colour shift is a healthy, temporary adaptation to cold and bright light.

No action required.Copper or bronze Winter colour is normal, non‑harmful, and a sign the plant is adapting successfully to cold conditions. Foliage will return to green as temperatures rise and metabolism increases in Spring.If desired, you can support overall Winter health by ensuring:Soil moisture is consistent but not waterloggedMulch is maintained around the root zonePlants are not exposed to sudden freeze–thaw cycles (e.g., reflected heat from buildings)Quote: “Temporary reddening caused by a combination of cold and sun is not harmful to plants and is a sign they’re adapting successfully to their environment.” — Dan Cooper Garden.