The Kurrajong bag moth has been prevalent this season, warns gardening writer JACKIE WARBURTON.

The green Kurrajong bag moth caterpillars group together in summer and autumn. They protect themselves by rolling a shelter of leaves with silk until a mass is formed.

The caterpillars shelter during the day and emerge at night to feed on young fresh foliage leaving skeletonised leaves behind. 

While they can cause damage to Kurrajongs (Brachychiton populneus), they won’t kill the tree, a tough and hardy native to eastern Australia. Affected trees usually recover. 

The caterpillar is small – only about two centimetres long – and emerges into a bright yellow adult moth with black zig-zag lines on its wings.

They are nocturnally attractive to light, so ensuring there are no night lights around the Kurrajong tree can limit them. 

All Kurrajong species can be affected, with the most damage occurring in the Kurrajong tree (B.populneus) and the Queensland bottle tree (B.rupestris). Both of these slow-growing trees can be seen at the National Arboretum. They are now a good size and don’t seem to have been affected by the moth. 

The Kurrajong tree can also be seen in local bushland.

To grow a Kurrajong: the seeds are ripe when the pods are dry and begin to open. Seeds can be soaked in lukewarm water overnight and placed in seed-raising mix and kept in a warm place to germinate, which can take up to four weeks in optimum growing conditions. 

Putting small seedlings in pots benefits their growth and ensures the root system is not disturbed to keep them growing fast. 

Once a small plant is a good size they can be planted into the ground. They have very invasive root systems, so ensure they are away from the foundations of buildings or water pipes. 

They can also be a little fickle to grow and need a good amount of nitrogen, phosphorus and potassium to grow well. If stressed, they drop their leaves in summer or if their water intake is diminished for survival. 

The flowers are beautiful bell-shaped petals that are attractive to all birds and pollinators. 

On rare occasions there can be a parasitic mistletoe that can live off this tree and will take over if given the chance.

The mistletoe foliage and flowers are different from the Kurrajong. They are easily identifiable and should be removed when seen or the mistletoe may kill the tree.

WITH most trees and shrubs dormant, there is little colour in the garden. But the vegetable patch can be a vibrant space by growing edible, ornamental kale. Popular with florists, these small plants are biannual, that is they grow the first year and set seed the second year.

They like to grow in colder climates and will bolt to seed once the weather warms.

Another advantage of growing these plants in the winter time is that the cabbage moth is not around, so no spraying of netting is needed. Ornamental kale has frilly, ruffled leaves. Green kale, with broad, flat leaves, is a little more palatable than its counterpart.

A little bitter to the taste, ornamental kale is generally used as a garnish for winter dishes. To combat this, the leaves can be softened by massaging them with lemon to break down the texture, making them easier to chew and less bitter. 

Jottings

• Apple, pear and pome trees can be pruned now. 

• Prepare soils for tree planting in the next few months. 

• Divide rhubarb and replant. 

• Plant wallflowers for late winter colour. 

jackwar@home.netspeed.com.au