Green With Envy: Sabrina Hahn Answers Reader Questions on Soil, Passionfruit, and Frangipani
Each week, gardening expert Sabrina Hahn delves into the most pressing problems faced by West Australian green thumbs. In this edition, she offers solutions for a struggling frangipani, guides on passionfruit maintenance, and explains how to find the best soil for your garden. Readers can submit their questions to the Green With Envy column, published in Saturday's The West Australian, by writing to Ask Sabrina, GPO Box D162, Perth 6001 or emailing home@wanews.com.au. Please include your full name and suburb. Due to high volume, not all queries will be answered.
Tough Love for Passionfruit Vines
Des Hazel from Waikiki asked about pruning passionfruit vines planted to cover a fence until shrubs grow into a hedge. Sabrina advises letting the passionfruit thrive for now and giving it a light prune in spring. She emphasizes that more energy into the vine in early stages leads to better health. Apply sulphate of potash in spring to encourage flower formation during summer months, ensuring robust growth and productivity.
Stopping Rot in Frangipani Trees
Janienne Wood from Canning Vale reported skinny branches and poor appearance at the tops of her frangipani tree. Sabrina identifies wrinkling and shrivelling as signs of rot in the root system or stems. She recommends pruning affected stems before cold weather sets in to prevent spread, spraying with Yates Anti Rot Phosacid, reducing watering to twice weekly, and avoiding fertilisation. While flowering may be impacted next summer, this approach saves the tree from total loss.
Root Issues with Ornamental Pear Trees
Ian Bevan from Landsdale inquired about ornamental pear trees allegedly lifting pavers and damaging a neighbour's bathroom. Sabrina explains that these trees can sucker and send surface roots that might lift paving, but it's unlikely to harm cement floors. She suggests cutting off problem roots after lifting paving, which may temporarily affect upper growth but is preferable to removing the entire tree.
Soil Matters for Crepe Myrtles
Katie Hill from Shenton Park described a crepe myrtle with pale-edged leaves despite soil treatments and irrigation. Sabrina notes that crepe myrtles prefer heavier soil with clay, manure, and compost, plus a quality fertiliser like Eco Growth Premium with wetting agent every five weeks in summer. Instead of iron chelates, she recommends foliar spraying with a complete trace element spray, such as Liquid Trace, fortnightly until deficiency symptoms disappear.
Sourcing Quality Soil from the Ground Up
Dominic Spagnolo from Mt Lawley sought advice on obtaining good quality soil after removing a large lemon tree, wary of weed contaminants from pre-bagged options. Sabrina suggests sourcing compost and soil improver directly from composting companies that heat-treat to eliminate pathogens and weed seeds, or checking landscape yards and garden centres for C-Wise products. The Green Life Soil Co offers high-standard blends tailored to different garden types.
