In the past few weeks I have many questions from readers relating to one of the most common and destructive of garden pests, the aphid.
Aphids top a gardener’s list of the “most hated” insect pests. Aphids are small sap-sucking pests about 1-2mm long. They are sometimes referred to as ‘greenfly’ or ‘black-fly’, although there is a range of body colors including white. They love almost all vegetables and ornamentals. Roses and fruit trees are especially vulnerable to aphid attack. They love roses.
Symptoms of aphid infestation include curled and wilted leaves, deformed fruit and flowers, and honeydew secretions on the plant. You will usually see many ants, which like to feed off the honeydew that the aphids secrete. If you have aphids, there will most likely be many ants present on the infested plant. Indeed in the event of an aphid attack most gardeners notice the ants first, myself included.
It is best for your plants and your environment if you can control pests with organic methods. Fortunately, aphids can be controlled well with several techniques, and chemical controls can be avoided. Once aphids are noticed, act fast. They multiply fast and they can suck vital nutrients from plants and spread deadly plant viruses. Most aphids feed on the above ground parts of plants, though some do attack roots.
An effective control for aphids is an easy to make soap spray. Mix three tablespoons of dishwashing liquid to ½ litre of water. Spray the plant where you see the aphids, don’t forget to look underneath the leaves too. The soap spray results in aphid death in about an hour. Some plants can suffer leaf burn if the soap spray stays on too long so would advise you to hose the residue off after about 90 minutes.
My favorite aphid remedy is made from food. The markets in Bali are full of chilli (cabe) and garlic (bawang). My aphid remedy combines five hot chillis, and five medium cloves of garlic and a liter of water. Mix everything in a blender until the garlic is minced, and then spray it directly onto plants.
An option for aphid prevention is to plant basil in many spots in the garden. Aphids are repelled by the smell of the basil and you can also use it in your cooking. Some gardeners even claim that basil repels mosquitoes. If you really must spray something chemical on the aphids, insecticide soap will kill them, as will Neem.
Now onto a garden pest of a different kind. Much larger and noisier than an aphid, I am referring to man’s best friend: the humble canine.
One of my readers writes:
“One of our dogs is in the habit of regularly urinating in our garden, as a result we have a lot of patches of dead grass on our lawn. We have tried to teach the dog not to, but without much success. So now we are looking for a type of grass that is more resistant to dog urine.”
Well in response, there are varieties of grass that are very durable, but no grass will be completely resistant to dog urine. Buffalo grass would be my personal choice. Buffalo grass is common throughout Bali, and it is very drought resistant and a strong, versatile grass.
Yes, dog urine will kill grass, and no grass is completely resistant to dog urine. Some people believe that the brown patches occur on the lawn because the urine is acidic and caustic to the grass. The real cause for the dead grass is nitrogen. Canines eat a diet that consists of high levels of protein. When proteins are digested they are eventually excreted as nitrogen in the dogs urine.
The excess nitrogen is what kills the lawn. The same burn will occur if a handful of fertilizer is applied directly onto one spot of the lawn. Nitrogen is fertilizer. So when a dog consistently urinates on the same spot on the lawn that spot becomes over fertilized and thus burnt. If you are using fertilizer on a dog-affected lawn, then you should probably stop. Any grass will burn if too much undiluted nitrogen is added.
The best solution is to regularly water. Watering the lawn daily helps the affected area by washing the urine through the ground before it can burn the grass. You should try and water the garden daily, or as soon as your dog has ‘done the business’. If you see the dog urinating on the lawn, water that area as soon as possible to dilute the nitrogen. You will probably notice that the dead patches are worse during dry weather, when the grass is more dry and stressed. Lawns stressed from drought are often more susceptible to urine spots and nitrogen burns the lawn faster when it is hot.
So in short the quickest solution, without ripping up and re-seeding your lawn, is to water the trouble spots regularly. You can try to revive brown spots by sprinkling sugar on top and adding lots of water. The sugar should act as a carbon and neutralize the excess nitrogen.
There is also a new product on the market called ‘dog rocks’ which consists of mineralized rocks. It is claimed the rocks added to the dogs water alters the nitrogen levels, without altering the pH level of the water, and claims to stop dogs staining the grass.
Alternatively, simply adding more water to your dog’s diet can help dilute urine, leading to less concentrated nitrogen deposits, and a less-affected lawn. The simplest solution would be to try and water the lawn more often.
