“Prune deciduous trees and shrubs once they have lost their leaves,” says gardening columnist CEDRIC BRYANT. 

THE first frosts have arrived, gently at first and increasing in intensity.

It’s like an air-raid siren, warning what’s ahead. Place any frost-sensitive plants in pots under the eaves of the home, though it may not be feasible with citrus in large containers. If the house doesn’t have wide enough overhanging eaves, and if the plants are not too tall, place four tomato stakes around the pot and cover with hessian or a dense shade cloth.

Now is the time to disconnect any plastic watering timers. When turned off, they usually still have some water in them and with a decent frost they will literally split open. Likewise, take off any sprinklers or garden watering wands on the end of hoses. Then disconnect garden hoses and put them under cover at night. Move indoor plants away from cold, draughty windows and also from ducted heating vents. These extremes can have a dramatic effect on your plant’s survival. Also reduce the frequency of watering, without letting the soil completely dry out. 

It’s a good time to prune deciduous trees and shrubs once they have lost their leaves. But do not prune spring flowering blossom trees or shrubs as you will cut off all the blossom buds. 

Prune deciduous ornamental trees now, as opposed to spring when many will bleed profusely as the sap is rising at that time. The main reason for pruning is to remove obvious dead branches and crossing branches. Betula pendula, or silver birch, is a real bleeder when pruned in spring. Deciduous trees should never be pruned between the first week in September and the last week in October. Also a no-no is the use of pruning paint on tree wounds. This is usually bituminous based and will inhibit the natural healing of the wound.

I DON’T recommend planting citrus at this time of the year, as we just don’t know how cold the winter is going to be. Wait until middle or late spring. In days gone by, when virtually every home had a Rayburn wood heater with the accompanying brick chimney, folk planted citrus alongside the chimney; the bricks would put out heat all night keeping frosts at bay!

On the subject of citrus; lemons, limes and kumquats all grow well in Canberra. The exception is oranges. Some readers tell me their oranges grow well, but in my experience owning a nursery in Yass for many years, and after more than 30 years involved with gardens in Canberra, I’ve found that they will grow and develop fruit, but never juice up. Oranges need a longer, hotter climate than here, such as in the Riverina. 

FALLING leaves can cause real problems on small plants and in particular dwarf hedges such as buxus and hebe. The weight of leaves when wet is considerable and can cause dead patches in the hedge. 

I MUST mention one very interesting small evergreen tree, Cornus capitata, a variety of dogwood. Found originally in the Himalaya by plant hunters back in 1822. In 1922 the Royal Horticultural Society gave it the prestigious Award of Garden Merit for its flowers and again in 1974 for its distinctive fruit. This time
of year it’s covered with strawberry-like berries, not edible, and a magnificent display of flowers which start off pale lemon yellow fading to a beautiful pink.

A NOTE on planting hedges of all sizes. Always dig a trench rather than individual holes. This way the roots will spread sideways considerably faster.