I mentioned a few weeks ago in this column about the huge incidence of Cupressus Bark Beetle and the Pine Moth in conifers this year. They are a problem in any year when there’s high rainfall or poor drainage, but it’s the treatment that is the problem. Although systemic insecticides such as Confidor were recommended, I have since discovered that they are not very effective.

This is because the larvae do not feed on the soft cambium tissue for long enough. They eat the white hardwood that is virtually dead and not taking up the active agent. After consulting ‘Frank’ Ugody the senior statesman of tree management in this region, I found that control could be gained by using the active agent chlorpyrifos as a spray onto the trunks, and within the canopy. The same active agent is used to control ants and cockroaches. It remains residual for 2-5 months depending on rainfall, so needs to be applied carefully. Apply in Oct-Nov and again in Dec-Jan.

You’ve probably planted your tomatoes by now and even if they are still in pots, make sure you keep all the thistles cleared for at least 50 metres all round. The common milk thistle is the prime host for the brown leafhopper that spreads the disease that causes big bud on tomatoes and eggplants preventing your bushes from fruiting. So keep pulling those thistles up!

The superb indoor begonias known as ‘Elator hybrids’ need repotting now that they are breaking into growth. If repotted with fresh potting media too soon in their growth season they frequently rot off, but now is fine. Sit the tuberous root so that the neck is just out of the potting mix and water by immersion until they get to be 10cm tall, or cold water on their leaves can cause leaf rot also.

I’ve had calls to my Sunday ABC radio program from folk concerned that their seedlings are wilting even though they have watered religiously. During the spring to summer transition we often get plants that make very soft growth and so when a few hours of warm weather strike, they flag or wilt. It’s not permanent, but caused by rapid soft growth and no amount of watering combats it so ….do nothing.

You’ve probably planted your first tomatoes by now and even if they are still in pots, make sure you keep all the thistles cleared for at least 50 metres all round. The common milk thistle is the prime host for the brown leafhopper that spreads the disease that causes big bud on tomatoes and eggplants preventing your bushes from fruiting. So keep pulling those thistles up!

Occasionally I see and hear my gardening peers say things that are at best suspect. One was recently when I was told and expected to believe that marigolds will prevent weeds. In your Mancunian dreams. While the perennial marigold, which is hardly grown in Australia, does have some allelopathic deterrent after 12 months in the soil, that prevents all seeds from germinating in its presence, the annual marigolds have no such effect.

If you are not a dab hand at growing lilies, try the Asiatic lilies next autumn. Vivid colours on short plants up to 45cm tall and so easily grown. Just provide good drainage and a sunny spot. Feed them with water-soluble fertilizer when they break into growth not long after planting. You see their bulbs on offer in autumn or order them from the usual mail order catalogues.

For growers of native plants such as Correas, Callistemon, Leptospermum and Melaleucas, it’s time to give them a light prune, so that they make lateral growths from which their flowers will rise next winter-spring.

White flies are rampant on the Ash trees, Day lilies, carrots and lots of other plants right now. I get good control using the yellow sticky traps. The sticky stuff attracts the flies and stays sticky even in rain. Available from some stores or from my website $9.50 for 5 pads posted anywhere.