Aphid infestations can destroy an entire plant, and will spread to all your other plants slowing destroying all your plants if left untreated.
How to kill these pests without using harmful chemicals?
Just lately we planted some new cabbage plants and a week later there were a lot of aphids attacking the plants, you could see the leaf of the plants curling back and we also had some on the tomato plants that they were starting to attack.
The treatment we used was getting an empty spray bottle 750ml filling it with water and adding two tablespoons of washing up liquid and we also added 20ml of liquid seaweed and sprayed this solution on morning and evening after three days of spraying all the aphid where gone. You can also kill a few with your hands. The reason we added the liquid seaweed is that the plant is under stress from the attack form the aphid and the seaweed will help the plants recover better.
Now that they are gone I made up a garlic spray by just crushing five cloves of garlic and putting the in warm water of an hour the filtering before adding the spray bottle. We spray this on all the plants once a day morning or evening. Our next step is to some onions and garlic close to the plants effected.
Hope this will help of you have this problem
Let me know how you get on,