It’s Canberra Tree Week and the right time to plan to plant a tree in the garden when most trees are deciduous, dormant and have no leaves, says gardening columnist JACKIE WARBURTON. 

If autumnal colour is what you’re after in the garden, then choosing a tree at this time of year will ensure you get the foliage colour you like. 

Planting trees should be done properly to get them off to a good start. The hole for planting a tree should be double the width and depth of the pot and, if possible, try not to make the side of the hole flat and smooth. 

Fill the hole with compost and mix with existing soil. Back fill the hole and tamp down the soil and water in. If the edges of the hole are rough, the water and roots will move better through the soil and help the tree to grow stronger. If this step is not done properly, the tree may be stunted and not grow well in rock-hard Canberra clay soils that hold moisture and cause root rot. 

Planting trees for future shade and privacy is important as it will be there for a long time. Once planted, only fertilise trees in the growing period when they have leaves. Mulch in winter with organic mulch or compost.

ORNAMENTAL grape vines will be putting on all their autumnal colour now and can look spectacular over a pergola or a large fence as their brilliant scarlet-coloured foliage fades and the vine goes into winter dormancy. 

They put on phenomenal growth in one season and can grow at least eight metres long. Grape vine’s (Vitis vinifera) have tendrils that are thigmotropic, that is when the vine touches anything, it grows modified stems to twine around supports for the plant to grow and stabilise itself.

In winter, pruning grape vines is crucial and should be done when the vine is dormant and there is no sap rising from the cut or wound. To assess if the vine has gone into full dormancy, do a test cut to see if the vine “weeps”. If it is, wait a little longer to prune. 

I get best results pruning in autumn to early winter as Canberra winter weather in July and August can be too moist, giving an entry point for fungal diseases. 

If ornamental or eating grapes had fungal issues last season, then a winter spray of a copper fungicide or a wettable sulphur will work and also aids as a miticide to prevent blistering on the leaves in spring. 

Apply a few times over winter and this will assist in preventing problems next season. 

Ornamental grapes can be cut back hard to a few stems in winter to try and keep some of the growth down and help with air flow to keep any diseases at bay. 

Eating-grape vines are pruned differently. They need spurs to grow flowering fruit and are pruned the same as wisteria. 

Once grapevines are established, they are drought hardy and don’t need much water. If pruning in autumn, the stems will be more flexible and can be used in the garden to make shapes and sculptures for a bit of fun that will last for a few years if kept dry. 

Jottings

• Remove spent foliage on perennials, cut up and place in the compost bin. 
• Keep Asian greens, kale and winter vegetables watered and add seaweed solution. 
• Remove growth on asparagus and dust the garden bed with lime and mulch. 
• Final watering for succulents until spring. 

jackwar@home.netspeed.com.au