Aphids on new leaf growth
Aphids hate the cold. At the moment, with the unusually warm weather they are thriving in protected micro-climates in gardens all over Melbourne. Today, when I was out pottering in the garden, I noticed that all of my parsley and coriander plants were covered in aphids. The plants have been quite close to a north facing brick wall, so it’s probably been warm enough for them to flourish. At least it’s a great excuse to get out the macro lens and take some snaps.
Aphids on a new parsley leaf
In small numbers aphids are not a problem. In larger numbers such as these, they can really knock young plants about. They are sap suckers, and love to congregate on new growth.
It’s easy to spot aphids. If you notice your plants starting to get unusually curling leaves, or looking a bit poorly take a closer look. Examine the new growth of the plant, and especially on the undersides of the leaves. At their maximum they are the size of a pin head, but can be much smaller. They can be green or black.
If you find aphids on your plants you have a few organic control methods at your disposal:
- Wipe them off with your fingers: this probably wont get them all, but will reduce the numbers.
- Spray the plants with a jet of water: this should knock them off the plant and disturb them.
- Spray the plants with a diluted white oil solution made from detergent and vegetable oil.
Given their large numbers on my plants, I opted to wipe them off with my fingers and then spray with white oil. I’ve also moved the plants out to the middle of the yard, away from the protection of the house. Hopefully spending a few nights out in the cold will be the final nail in their coffin!
Aphids come in many colours and sizes
A close-up of aphids on a new parsley leaf
Close up of aphids on a coriander leaf
My potted lemon tree has been under attack, I have removed most of the eaten leaves, and removed most of the lemons as they were browning at the stem and would probably drop anyway, they also had marks on some branches, like track marks..now my 2 planted out plum trees are showing the same signs…I can’t see anything eating them, would the white oil also fix this?
Hi Jenny,
Without seeing the trees it is difficult for me to diagnose what the issues may be. Aphids shouldn’t “eat” leaves. They are sap suckers. So there wont be any holes or chew marks left by aphids. It is always important to correctly identify whatever the “problem” is before deciding on a course of action. In any case usually pest attack has a limited outcome on the health and yield of the tree. If pests are having a large negative impact on either of these, then it is likely to be the wrong tree in the wrong spot!
Good Luck & Happy Gardening
Duncan