Fungal infections can occur on wounded plants located in situations ideal for the fungi to thrive — for example, bean rust thrives in warm, moist conditions, and common potato scab is a problem in very alkaline soils.
Most plant fungal infections are encouraged by humid conditions aggravated by crowded plants with poor ventilation, and watering in the evening. Simply change these conditions by thinning the foliage and watering early in the day.
It is also important to rid the system of fungal spores whenever possible. Seal all infected plant material in plastic bags and bin it — never add it to the compost heap. Also sterilise garden tools and support stakes.
If good management fails to give adequate control of pests or diseases problems can be treated with an expanding range of natural organic substances. Aim to use products that are target — specific rather than broad spectrum, as the latter can harm beneficial organisms as well.
One year’s seeding and many years of weeding
It is crucial to remove weeds before they flower and set seed. Weeds can be smothered with newspaper, sawdust and thick mulch. A good groundcover will reduce the opportunity for weeds to establish.
Many gardeners find it acceptable to use glyphosate on stubborn weeds because, although it is a chemical, it does not affect the soil structure and may not affect anything else provided you wipe it on instead of spraying.
Using uncomposted manure to build up soil can also lead to weed introductions. Doublegee seeds can be brought into the garden in horse and sheep manure and wild oats seeds can be in bales of straw. Mulch with hay instead of straw.
Research a plant’s growth habit before introducing it into your garden as many vigorous ones have the capacity to become weeds of gardens and bushland.
Aquatic plants will shelter fish in ponds from birds, but never use salvinia and water hyacinth as they are serious weeds of waterways and are prohibited in Western Australia.