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Sustainable Gardening- Soils ain’t Soils The morning dews!

Its official- winter it is, and the temperatures have finally dropped accordingly but those very damp weather conditions we experienced in autumn really promoted some serious fungal activity around the place also. Myrtle rust is still plaguing some of our native plants and there has been a lot of pest pressure affecting citrus also, with leaf miner, aphids, scale and mealy bug-to name a few. Frangipani rust has also been rampant in the district due to all the humid weather in the last couple of months, which has contributed to full blown infections on some trees around the coast, causing premature leaf drop on some of the deciduous species and stunting the growth on some of the Plumeria obtusa, especially the younger trees. If your citrus trees have been hammered, then it’s a good time to prune any badly diseased or distorted foliage off and treat with some seaweed tonics all over before the next flower set. Myrtle rust can be a real pain to treat but if the outbreak is treatable (able to prune the diseased foliage off at a manageable height), then pruning these plants a few days after treatment with a (registered fungicide), will be beneficial. More info here:

Check the website on APVMA= Australian Pesticides and Veterinary Medicines Authority- for current registered permits for allowed chemicals- . All pruning matter should be bagged, sealed and disposed of in the bin to prevent further spread of the fungal spores on your property- and don’t forget to sterilise your pruning equipment afterwards. I have found that some species like- Gossia inophloia- ‘Blushing Beauty’, Syzygium jambos, and Callistemon- ‘Great Balls of Fire’ are getting infected year after year with myrtle rust. The disease is so well established now that I always advise my clients to the potential of infection of known vulnerable species when collaborating on new garden designs together and recommend another suitable hardy plant that may suffice in its place. If you are pruning multiple shrubs from one plant to another in your garden without sterilising your cutting equipment, you may find you are unwittingly- spreading the disease around and possibly infecting some of the other native plants from the Myrtaceae family too, like: Tea trees, lemon myrtle or bottle brush. Hygiene practices, with keen observation, by regular inspecting the leaves, stems and fallen fruit for any sign of pest and disease problems will assist greatly in early diagnosis, for immediate treatment. Non systemic (protective treatments) -which do not cure- fungal diseases, are treatments that use products such as copper oxychloride or Mancozeb (allowed for myrtle rust) and lime sulphur or potassium bicarbonate for geranium rust or powdery mildew. These must be applied to all leaves, stems and fruit to be effective but the timing between wet weather episodes is critical. Obviously, the humidity contributes to the establishment of fungal diseases in lawns and plants, so the effectiveness of the above products becomes limited due to the onset of any rain periods which can wash off the active ingredients into the soil profile, which can also have a negative effect on the microbial soil life (especially with copper). Another good option is to try and bring the nutrition levels up with a slow release, Australian native plant- friendly, organic fertiliser- to help fortify and aid in the plant’s recovery (Seaweed- may assist here). Well that’s all on fungal diseases this issue. May your plants- live long and prosper! - The Happy Horticulturist.

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