Keeping your garden safe from pests and diseases this summer


It’s summer and thankfully the rain is here. Plants are flourishing but pests and diseases may attack your garden because abundant food and moisture is available. At GardenShop we try to promote organic solutions as far as possible. It must be mentioned that a healthy soil promotes healthy plants, so correct soil preparation on planting, and seasonal fertilising is essential for plants to remain strong and healthy.

Listed below are prevalent pests and diseases and how to manage them, so that they don’t cause too much destruction ahead of the holiday season.

  • Snails and Slug

Snails love moist conditions, it makes it easier for them to move around and to breed. Snails and slugs like to eat on fleshy plants like Agapanthus, Wild Rhubarb, Clivias, Arum Lilies, Hosta and other fleshy plants.


For an organic option, you can use Biogrow Ferramol.

The Johannesburg Wildlife Veterinary Hospital is situated at 101 Macgilivray in Glenfinesse and is always in desperate need of snails to feed their patients. They will even come and collect! (And they also accept veggies for the tortoises)

For small or selected treatment areas, biological snail baits and snail traps can be used, like beer traps and crushed egg shells. Snailban is a well-known chemical pellet product which you scatter on the ground in infested areas. For large areas, it is may be easier to spray plants with Efekto Snailflo.

  • Caterpillar

Caterpillars have hatched and need to feed on plants so they can metamorphosize into moths or beautiful butterflies. Caterpillars in large numbers can cause a lot of damage. Keep your eyes peeled when walking through your garden for any problems that require immediate treatment. Caterpillars are commonly found on Clivias and Citrus trees.


For best treatment on Clivias and Agapanthus, spray plants with Protek Knox Worm. Alternatively use Margret Roberts Biological Caterpillar Insecticide. For best treatment on Citrus, spray plants with Efekto Oleum. This is a mineral oil and completely non-toxic.

  • Mealie Bug

Mealie bug is a white insect commonly found in groups where a cotton-like substance is covering the plant. Mealie bug is commonly found attacking Orchids, Aglanema, indoor palms and many other plants. They generally like sheltered places so they are easy to identify when a problem begins.


Organic treatments include Ludwig’s Insect Spray + which contains a natural pyrethroid or Efekto Oleum. Alternatively any of the following Efekto products will work too. Malasol, Cypermethrin, or Aphicide. With bark-soils treat the root area too by drenching the soil.

  • Chafer Beetle

Also known as the ‘Christmas Beetle’, this brown beetle comes out at night and eats the leaves of plants, leaving them lacy and bare. Commonly attacking Roses and Fuchsia, one needs to treat systemically. 


Unfortunately organic bio-pesticide control is usually not successful when the adult stage is targeted. If populations are severe target with Efekto Karbaspray. Avoid using this product on edible plants.

Listed are common diseases that are likely to spread during the wet warm weather.

  • Black Spot

Black spot is a fungus that develops within the foliage of some plants during wet conditions. Black spots appear on the leaves in different sizes then the leaves will turn yellow and fall off. Roses and Aloes commonly get black spot.


Avoid watering the leaves of roses, water them at their base. Avoid over watering Aloes. Margaret Roberts Organic Fungicide can be sprayed. Alternatively infected plants can be sprayed with Efekto Funginex.

  • Rust

Summer is hot and at times wet, hot humid conditions leads to the development of rust on plants. Rust looks like an orange powder under the leaves causing the leaves to become yellow and sickly. Common plants that can get rust are Day Lilies, Fuchsias, Strawberries, Irises and more. 


Thin out plants if the infected plants are tightly planted as with Day Lilies, this will increase air movement between the plants which lowers the risk of rust development. Other infected plants could need a bit of a pruning to increase air movement.

More to explorer

Leave a Reply