Prevention is better (and easier) than cure!
Inspect your plants frequently to detect AND treat pests and disease early.
Feed your plants to increase resistance and repair capabilities.
Avoid overcrowding – do not grow more plants that you can handle.
Ensure adequate ventilation.
Avoid overwatering – water in early morning. At temperatures higher than 30°C plants absorb and transpire water with difficulty and excess watering may drown plants. Mist or dampen floor, encourage ventilation. Look at weather reports and prepare for a hot day! Young plants in large pots are vulnerable!
Never let the root ball dry out completely – the hair roots die first and water cannot be absorbed – risk of drowing – water from underneath (saucer) and mist spray.
Hygiene – remove all dead/dying/diseased plant material soonest. Clean pots with a disinfectant like Jeyes Fluid before re-use.
Adjust temperature and humidity – where possible – some pests like it hot and dry (Whitefly and red spider mite), some like it cold and wet (rust and botrytis) – make them uncomfortable!
Pruning with defoliation in autumn will remove all pests and diseases.
Many pests are brought in by new plants – quarantine new plants for a few weeks.
Precautions when spraying en masse:
Protective clothing – long sleeved shirt, long trousers, masks, cap (if bald!), glasses or goggles and gloves allow you to pick up plants to spray underneath leaves. Cleanse and rinse spraying apparatus, change/wash clothing and shower. Store in safe place, in original labelled containers.
Remember wet sprays mark flowers and buds. Ensure a pest-free environment well before the show – USE PREVENTATIVE SPRAYING.
Spray in early morning or evening when there is less wind and it is cooler – catch the beasties napping! Spray downwind if there is a breeze! Spray for total coverage under and upper surfaces of leaves, and stems, but don’t make them dripping wet! Do not spray just before rain is expected.
Read instructions carefully – the recommended does is what works! An insect needs only to be killed once, and you risk damage to your plants! Useful insects may also be killed.
For a few plants use one of the insecticide/fungicide ‘GUNS’, but still be careful.
Contact insecticides/fungicides only work on contact and often only kill the adult pest, but do give quick results – spray several times at intervals of 4-5 days to catch successive generations before they can breed.
Systemic insecticides and fungicides are watered into moist soil or sprayed on foliage, taken up by the roots/leaves and make the sap poisonous to the pests. Efekto insecticide granules are an alternative. They give more prolonged protection, but act more slowly.