Our dog’s wee is killing off the lawn. How can we stop it?

High nitrogen and lactic acid levels in dogs’ urine literally burn lawn, causing brown or dead patches. Helen Young gives some tips to lessen the impact.

Ripe fresh mandarins.

Scroll to the below Gardening Q&A section to read more about how to lessen the impact of dog urine on lawns.

Like most citrus, mandarins are attractive small-to-medium evergreen trees with glossy leaves and fragrant white flowers. Their dense foliage makes them a good screening tree, and they fruit easily given full sun, good soil, regular water and fertiliser. A mature tree can produce hundreds of fruit. Mandarins ripen from April to October, depending on the variety and climate – so if you have enough room, choose an early, a mid and a late-maturing variety for fruit over six months. This also avoids cross-pollination between different varieties that flower together, which would result in increased seed formation. In small gardens or for pots, choose a variety grafted onto dwarfing rootstock. ‘Imperial’ is a popular, early variety that peels easily and has some seeds. ‘Emperor’ bears large, easily peeled fruit mid-season, also with seeds. It and ‘Ellendale’ are more cold-tolerant varieties. ‘Daisy’ has large, juicy fruit whose rind is almost red, while ‘Afourer’ is a mid-to-late season variety that peels easily, has few seeds and intense flavour. A late variety is ‘Honey Murcott’ – its thinner skin is harder to peel but it’s flavoursome. For something different, try large and seedless ‘Sumo’ with its bumpy skin and “top knot” shape.

Flowering Plants - In the Cone

Leucadendrons, or cone bushes, come from South Africa but enjoy similar conditions to our related native species such as banksias and grevilleas.

Leucadendron ‘Red Devil’

Leucadendron ‘Amy’

They have striking coloured new foliage and flowers, and last very well in a vase. These four are winter flowering.

Leucadendron ‘Winter Gold’

Leucadendron ‘Safari Sunset’

Q&A

Our garden is over-run with rabbits. We’ve heard a sonic device might deter them but would it also affect our cocker spaniel?

Barbara Pyett, Pearcedale, Vic

Ultrasonic repellent devices emit a sound that humans mostly can’t hear but irritates and confuses pests such as rabbits. Depending on the frequency and the volume, it’s possible your dog would hear it; manufacturers suggest you test different settings with your pets or keep them away from the area. Choose a brand with a 30-day satisfaction guarantee. They can be solar powered, motion-activated, have flashing lights and/or eject bursts of water.

Our lemon tree has something that causes ugly, warty growths on the fruit, ruining their appearance. What is it and can we treat it? Will it spread to other fruit trees in the garden?

Paul Blackett, Sydney

This is citrus scab, a fungal disease that mostly affects lemons of all types but can affect limes, some mandarins and tangelos. Severe infections can cause twiggy branches to be unproductive, affect leaves and bark, and weaken the tree. The corky, warty scabs release spores that are spread by rain, birds and insects. Prune off and destroy affected growth. Spray copper hydroxide thoroughly as a preventative, three times over nine weeks, and repeat as new leaves form. Prune trees to keep them open and increase airflow.

Our large, neutered male dog is killing off our Sir Walter buffalo lawn with his urine. Any suggestions?

Jude Hines, Adelaide

High nitrogen and lactic acid levels in dogs’ urine literally burn the lawn, causing brown or dead patches. The more undigested protein and the less water your dog has, the stronger the urine. Hose over toilet spots immediately or train your dog to use a designated, mulched area. A product called “Dog Rocks” claims to prevent the problem but has no scientific evidence to support those claims.

Sloggers Outnabout boots.

Send your questions to: [e-mail]. The best question for June will win a pair of Sloggers Outnabout boots of your colour choice, worth $140.