Garden tips: flame trees, onion weed, gardenia, ginger

I’ve never seen my Illawarra flame tree flower and I’ve been here five years. Any suggestions?

Illawarra flame trees can take up to 20 years to flower.

I’ve never seen my Illawarra flame tree flower and I’ve been here five years. Any suggestions? - GAY WOOLLEY, YEPPOON, QUEENSLAND

Brachychiton acerifolius can take up to 20 years to flower. It is usually deciduous in the tropical dry season and flowers just before the new leaves appear in summer but can be erratic and sometimes flowers just on one side. Too much shade will prevent flowering and it’s possible possums are eating the flower buds.

I’d love to plant some flowers on my dear deceased pet’s grave. What would you recommend? - AMY PETERSEN, BRISBANE

Forget-me-nots are pretty spring annuals and self-seed readily. Tough summer annuals include vinca (Catharanthus roseus), which symbolises sweet remembrance, and spreading petunias. In the cool months grow pansies, which symbolise loving thoughts. For a more permanent plant, rosemary is for remembrance but needs a sunny, well-drained spot in your climate.

How can I exterminate onion weed from my lawn? I sprayed it carefully with Zero and the whole lawn died. Having re-laid lawn, I’m now on weekly patrol digging up the persistent onion weed. - LINDA ERHARDT, SYDNEY

Digging out the deep bulbs of onion weed can make it worse by dislodging and spreading the many tiny bulbils. Regular mowing weakens it. Alternatively, a professional lawn care company (such as Lawn Green in Sydney) can apply the commercial herbicide Destiny, which targets onion weed in most popular lawn grasses. It is not registered for home use so you cannot buy it retail or apply it yourself.

My potted gardenia receives lots of TLC and has healthy leaves and multitudes of buds. Sadly, the buds turn brown and drop before opening. What’s going wrong? - JANEL HAZELL, PERTH

It’s probably mealybug, a sucking pest that hides within the bud bases. You may see only fragments of white sticky or powdery residue; it can also live on the roots. Mealybug is hard to kill, resistant to many of the potent systemic pesticides. I’ve had most success when using Eco-Oil and Eco-Neem mixed together to treat scale and aphids, and found that coincidentally it treated mealybug. Eco-Neem is not yet registered in Australia for mealybug, but is overseas. You can also buy native ladybirds, Cryptolaemus, from goodbugs.com.au and ecoorganicgarden.com.au as a biological control.

Send your questions to: [e-mail] or Helen Young, PO Box 3098, Willoughby North, NSW 2068. Website: helenyoung.com.au. The best question for November wins the indispensable new 44th edition of Yates Garden Guide ($40) plus $40 worth of Yates organic seeds and garden products.

FLORAIn warmer climates, growing your own fresh ginger is rewarding and not too difficult. Zingiber officinalis sends up lush green stems from the knobbly rhizomes in spring, reaching up to 1m high and wide. Although a tropical plant, it grows further south in a warm, protected, lightly shaded spot, with ample water and fertiliser. You also can grow it in a large pot. Young, green shoots can be used any time, and some rhizomes harvested from the side of the clump after a few months, when they are juicy and tender. In early winter when the foliage dies down, lift, clean and use or store the rest. Small pots are available in selected nurseries now; phone Colourwise for stockists on 0245 666 177.