Common Pests, Diseases & Weeds.
All garden plants come under attack at some point from all kinds of pests and diseases. What we have done here is to catalogue the major culprits and give you a little bit of knowledge on how to deal with the problem effectively.
Prevention is the best form of defence against pest & diseases and good garden maintenance and plant hygiene is the most effective way of reducing serious problems.
A survey conducted recently listed the following as the top 10 pest and disease problems. It is worth noting that the order can change from year to year with climatic change and other variables. They are:
1. Slugs and snails
2. Greenfly (aphid)
3. Blackfly
4. Blackspot
5. Mildew
6. Whitefly
7. Caterpillars
8. Grey mould (botrytis)
9. Rust
10. Soil grubs (leatherjackets, cutworm etc)

SLUGS & SNAILS
A well tended garden is the perfect breeding ground for both plants and slugs/snails alike. They love the moist and warm conditions that plants thrive in. They can shred seedlings and leaves overnight causing the gardener must frustration.
Control will slug pellets at 10 day intervals or remove any shelter near your plants (pots etc) where the slug will disappear under during the day.
GREENFLY & BLACKFLY (aphid)
Greenfly and Blackfly are a phenomenal breeder – a single female adult can produce thousands in a few weeks. They feed on the plant and can spread diseases and viruses between plants.
Spraying to control these pests can also harm the beneficial insects in your garden. Consult the internet or your local garden centre for specific advice with regards to your problem. Your garden will also have natural predators of these flys. The only issue here is that they will take some time to knock out the greenfly & blackfly by which time a fair bit of damage to your plants can occur.
BLACKSPOT
Symptoms are dark spots with yellow edges on older leaves. Blackspot is a common fungal disease that overwinters on old leaves, on the stems and in the soil.
Regular pruning and mulching is a great way of cutting down blackspot infection of the plants.
MILDEW
The most common mildew is powdery followed by downy. Powdery mildew symptoms are generally a white residue/coating on the leaves and the stems. Downy mildew has a grey or purple mould on the underside of the leaf and patches on the upper side.
The best form of control is a chemical one. A systemic fungicide can be purchased from your local stockist. Make sure that the chemical is specifically used to combat powdery mildew or downy mildew.
WHITEFLY
The symptom is to have the undersides of the plant leaves covered in white insects. These are predominantly a greenhouse pest and can be quite tricky to remove once established.
Use of yellow greenhouse sticky traps will catch a lot of them as will spraying with a contact insecticide. You could also try some biological control using Encarsia (a parasitic wasp).
CATERPILLARS
Similar sort of damage to the plants as from slugs/snails but without the trail!
Control by manually picking off the affected leaves and the actual caterpillars and disposing of away from the crops in question. A contact insecticide can be used in the cases of infestation.
GREY MOULD (botrytis)
The symptoms are a grey powdery/fluffy mould covering the stems, leaves, buds and fruit of a plant. This disease normally attacks stressed plants. A healthy plant will be far less susceptible to an attack than a stressed one.
Control by removing the affected parts of the plants and disposing of them. Avoid damp conditions and spray with a fungicide as a preventative measure.
RUST
These are brown, red or orange powdery spots or streaks on leaves. This is a fungal disease and attacks a wide range of plants.
Spray at 10 day intervals to combat this or alternatively remove the affected leaves and dispose of (the preference is for burning).
SOIL GRUBS
Soil grubs feed either on roots or a surface level on stems. They generally feed at night time.
To control dig the soil near an affected area and take out the grubs and leave for the birds to eat. Alternatively you could use a soil insecticide – available from your local stockist.

WEEDS
Weeds are just about the most common (perennial) problem that any gardener has! There are three ways to eradicate weed problems: (a) hoeing, (b) mulching and© weed killing with chemicals.
• Hoeing – Needs to be done regularly to get on top of the annual weeds that grow just about as fast as you can hoe them. Hoe in the early morning leaving the weeds on the soil surface. The sun will then burn & kill them in the heat of the day.
• Mulching – Bark chippings or a soil improver, or indeed black plastic or an old carpet are very effective ways of mulching. Cover with a decent layer and just easily pick out any weeds that do get through.
• Chemicals – there are many chemicals available on the market now with the sole aim of killing weeds.