Each week, The West Australian's Sabrina Hahn addresses the most pressing dilemmas of home gardeners. This week, she tackles a struggling Polygala, a deteriorating hedge, an unhappy indoor plant, and provides guidance on what to do when seeds appear on a magnolia tree.
Snow Bush Hedge Woes
Susan Robertson from Wannanup writes about her hedge of 'confetti' plants in Mandurah, propagated from cuttings from Esperance. Over recent years, the plants have declined, suffering from aphid infestations and abnormal new growth. Neem oil provided only temporary relief. Sabrina identifies the plant as Breynia Nivosa Rosea, commonly known as snow bush. The damage may be from aphids or thrips. For long-term control, she recommends introducing predatory insects such as spotted ladybirds, lacewing larvae, and the predatory wasp Aphidius colemani, available from Bugs For Bugs. Avoid using sprays, as they harm both pests and beneficial insects.
Unhappy Happy Plant
Luisa Savill from Carine has a happy plant (Dracaena) over 20 years old, nearly touching the ceiling and becoming spindly. Sabrina explains the plant is searching for more light. She advises pruning it back by 50% to a node or ridge to encourage branching. After pruning, move the plant to a brighter location and start liquid fertilising monthly. Repotting into fresh potting mix with slow-release indoor fertiliser is also recommended.
Polygala with Black Dots
R. Jennings from Busselton reports a Polygala Little Charmer with black/purple dots on leaf undersides, causing leaf drop. Sabrina suspects a fungal issue, though rare in Polygala, possibly root rot. Once symptoms appear, it is often too late to save the plant.
Growing Magnolia from Seeds
Vicki Cooper from Dawesville asks about magnolia seeds that appeared on her tree. Sabrina outlines a process: remove the red outer coating to expose the black seed. Place seeds in a ziplock bag with moist cocopeat (not wet), seal, and refrigerate for three months to simulate winter (stratification). After that, pot the seeds in individual small pots with potting mix. This mimics nature, where birds eat seeds and drop them with fertiliser, awaiting spring germination.
To submit your own question to the Green With Envy column, write to Ask Sabrina, GPO Box D162, Perth 6001, or email home@wanews.com.au. Include your full name and suburb. Due to volume, not all questions can be answered.
