How to: fix your lemon

If our hotlines here at the Garden Clinic, and on Garden Clinic Radio on 2GB and 2UE are anything to go by, lemons cause gardeners much heartache.

We’re here to help! Here are solutions to six common lemon problems.

Pimples on leaves and stems

Pimples on leaves and stems are scale. These sap-sucking insects cause leaf drop and reduced plant vigour. Spray with Eco-oil, following up with further sprays as directed on the bottle. If you notice ants as well, you must control them too, as they protect scale from predators so they can enjoy their honeydew.

Sap-sucking insects like scale and mealy bug (pictured) cause leaf drop and reduced plant vigour.

No flowers or fruit

No flowers or fruit on an otherwise healthy tree are signs of either too much shade or not enough potassium. Lemons need six hours of full sun a day. If light is not the problem, apply sulphate of potash or liquid potash monthly - in addition to applications of citrus fertiliser at the change of every season. Continue until flowers form.

Lemons need six hours of full sun a day, and flowers need potassium

Leaf miner

Silvery trails or twisted new growth is caused by citrus leaf miner, which is the larvae of a tiny moth. As a preventative measure, spray with Eco-oilmonthly during the warmer months. If you see leaf damage, trim off the worst-affected growth and increase spraying to weekly. The Eco-CLM trap is very effective at reducing large populations.

If you see leaf miner damage trim off the worst-affected growth and increase spraying to weekly

Strink bugs

Bronze orange bugs are large, sap-sucking bugs. In big numbers they can cause flower and fruit drop. Deter them with monthly sprays of Eco-oilfrom late winter. If they arrive anyway use pyrethrum spray as a knockdown but protect yourself with sunglasses and protective clothing as they fight back by squirting a foul-smelling liquid. Nature’s Way Citrus & Ornamental Sprayis an effective combination of pyrethrum and oil to use against them.

Mature Bronze Orange Bug.

Fruit fly

Small holes in fruit and wrigglers inside are evidence of fruit fly attack. The female, which lays her eggs in the fruit, can be active from late winter until the end of autumn. Begin control measures as soon as flowers appear. There are various baits and traps on the market including Cera Trap, Eco-naturalure and Nature’s Way Fruit Fly Control. Follow the directions carefully. Fine gauge netting or exclusion bags are an alternative protection method; wait for the fruit to appear before covering.Practice good garden hygiene to reduce pest populations. Put infested fruit into sealed plastic bags in the garbage bin.

Fruit fly lay eggs in developing fruit

A pithy problem

Fruit with very thick rind and not much juice can be caused by heavy applications of high-nitrogen fertiliser, particularly if it is used from late summer. Use complete fertilisers developed for citrus at the beginning of each season. Adopt a systematic watering regime too, to keep the soil moisture level even.

Use complete fertilisers developed for citrus to avoid thick rind with not much juice