Neem oil is a popular product to use in the garden – it’s organic and safe around children, pets and plants, writes gardening writer JACKIE WARBURTON.

NEEM oil has hundreds of biological, antiviral and anti-bacterial properties and can be an immune stimulant in the garden as well. 

It can be used on foliage, bark and even the soils, but is most effective when it can translocate into the vascular system of the plants and insects chew on the foliage. Once the insects ingest it, it prevents the larvae from moulting and therefore cannot reproduce. 

Neem is unharmful to beneficial insects, and it’s biodegradable, decomposes rapidly and effectively on soft-bodied insects, including aphids, spider mite, caterpillars, beetles, snails and slugs. 

While costly, as little as two millilitres of neem oil for 200 millilitres of water is all that’s needed. However, overdosing on neem can lead to leaf burn and cause damage. 

All parts of the neem tree (Azadirachta indica) can be used, but the seed is the most potent and the common part used for horticultural insecticides. 

Its added bonus is as a fungicide. As a preventative spray, it can suppress several common leaf-spot diseases such as powdery and downy mildews. 

WINTER oils are generally petroleum based with paraffin their active ingredient. It’s a by-product of petrol, is low in toxicity and used only in winter on bare stems of fruit trees for harder-shelled insects such as cottony cushion scale, Californian red scale and beetles.

Australian-made eco oil is the safest to use in the garden and its active ingredient is 100 per cent plant oil and doesn’t contain petroleum. Eco oil smothers insects it comes in contact with. Eco oil and eco neem are compatible to mix together to do two jobs at once. 

AT this time of year, citrus will look its worst if it’s been planted in the wrong spot. It really won’t like the cold and frosts that damage its fruit.

The correct position in the garden will guarantee a thriving, long-lived evergreen fruit tree. Citrus trees like a northern wall to grow up against and plenty of winter sun. 

They like lots of organic matter and adding plenty of aged poultry, cow or horse manure in winter will get them growing strongly when spring arrives. 

The number of varieties is forever growing. The three ancestral citrus species, that originated from Asia and Oceania – mandarins, pomelos and citrons – have been cross bred to create oranges, lemons, limes and grapefruits and many more new varieties. 

Yuzu, one of the latest new citrus, is suitable for Canberra. This prized citrus is cold tolerant, highly fragrant and has a tart flavour. 

Its fruit should be peeled, chopped and added to meals, but not eaten in segments raw. 

Yuzu has yellow skin and is shaped like an orange. Its leaves can also be used in the kitchen to add flavour to curries and stir fries. 

A SMALL tree flowering now and right into the warmer weather is the old favourite, the winter rose or hellebore. Its dainty flowers sit above the ground in winter and are not bothered by frosts. 

There are double and single varieties available as well as many colours. It can be planted in the shade. 

Jottings 

• Remove annual weeds, such as sticky weed and vetch, before they flower. 

• Feed fruit trees with compost and organic matter.

• Add boron to the soil around apple trees for sweetness and crunch.

• Get seedling trays, potting mix and seeds ready for planting in a few weeks when the daily temperature increases.