Aphids on your plants: complete guide to get rid of them

Aphids are one of the most common and harmful pests both in our gardens and in the home. These small insects (green, black or white) feed on the sap of leaves and stems and are attracted by nutrient-rich fertilisers. They do a lot of harm to plants and make them more susceptible to disease. You should know that they are more active in spring and summer, with the higher temperatures and longer hours of sunlight.

We are going to teach you how to identify, effectively prevent and get rid of aphids from plants using natural, specific solutions to avoid them spreading and causing more damage to your garden or crops.
 

Types of aphids

There are different types of aphids because each species has adapted to specific conditions: different plants, climates, colours, even defences. This diversity allows them to survive, reproduce and spread in many different environments. 

Some of the most common ones are as follows:

• Greenfly. These are one of the most common species and their green colour makes them hard to see at first sight. They feed from a wide variety of plants, from rose bushes to market garden crops. They can transmit virus and seriously weaken our plants.
• Blackfly. They are common on some ornamental plants and also on beans, wallflowers and dahlias. They typically form large colonies on soft shoots and excrete a large amount of sticky paste which attracts ants and also favours the growth of fungi.
• Whitefly. What we commonly know as whitefly can also include cochineal, which are recognisable by their waxy, cotton-like appearance. They usually attack apple and citrus fruit trees and other woody species.
• Leaf-curl plum aphid. They stand out for their striking colour and usually attack oleander, periwinkles or carnations. They are particularly aggressive in warm climates and multiply very quickly.
• Cabbage fly. They are usually found on rose bushes and horticultural crops. They also produce a paste which entails the risk of fungi.
• Black cherry aphid. They particularly affect apple trees and other fruit plants. They usually appear in the spring and are obvious because of their red or orange colour. 
   

Effects of aphids on plants that you should know about

Aphids are not only aesthetically unpleasant, but their presence on plants is a serious threat to their general health. Among the effects of aphids on plants, the following are perhaps the most noteworthy: general wilting, leaf curl, yellow or deformed leaves, presence of a sticky paste, appearance of fungi (such as sooty mould) or ants.

Homemade remedies to combat aphids on your plants

If you would rather try some household remedies with products from around the house instead of using insecticides, you could try the following. It is important to always treat the plants at dawn or dusk to avoid hours of strongest sunlight and possibly causing the leaves to scorch. To ensure your plants remain healthy, we recommend applying these remedies for no more than 5 or 6 days.

• Soap and water. First spray a jet of water on the plant to wash off the insects, and then gently apply soapy water to each leaf using a sponge, paying special attention to the undersides of the leaves. Repeat the process again the next day. It is a laborious process, but very effective.
• Garlic. Garlic has bactericide properties and it is therefore useful to combat insects on plants. Boil some garlic cloves in water, allow it to stand for 24 hours and then pour it into a spray bottle to apply to the plants. Do this for 4 or 5 days and then wait several days to see the result.
• Vinegar. We recommend using wine vinegar since it is less acidic, but cider vinegar can also be used. Whichever variety of vinegar you use, it needs to be diluted in water to avoid damaging the plant. Add one soupspoon of vinegar to one litre of water. Then spray it on the plant, paying special attention to the infested parts.
• Tobacco. Nicotine can also be very effective to combat aphids. Take a couple of handfuls of loose tobacco and put it in one litre of water. Bring it to the boil. Then let it stand for a couple of days. Apply the liquid to the plant to clean it for 5 or 6 days and manually wipe off the insects until they disappear.
   

Insecticides for greenfly

Buying an insecticide when natural remedies don’t work can be a good decision for several reasons, since they tend to work quickly and are effective, and are particularly useful when the plants are seriously infested or the aphids are persistent. If you are wondering which insecticide is best for greenfly, you will be pleased to know that there are several options. We recommend always reading the label and instructions to avoid damaging your plants and the environment.

• Potassium soap insecticide. This is a natural, biodegradable product which is ideal for this purpose since it works by breaking down the membrane of insects and causing them to dehydrate. It is safe to use on organic crops.
• Neem seed oil. It is a natural insecticide and insect repellent made from the seeds of the neem tree. It interferes with the development and feeding of greenfly, and also works as a preventive treatment.
• Systemic insecticides. These are chemical products that are absorbed by the plants and kill aphids as they feed on the sap. They are usually effective against consolidated infestations and must be used carefully, following the instructions to the letter.
• Specific aphid sprays. The good thing about these products is that they work quickly and directly on the insects, therefore getting rid of them easily.

How to prevent aphids from appearing on your plants

The best strategy against aphids is prevention, because it is easier, safer and more effective to prevent them from appearing than getting rid of them once they have appeared. Therefore, you should do the following:

• Check: have a good look at your plants every day to detect the problem early and act accordingly.
• Combine “repellent” plants: aromatic plants such as basil, mint and coriander, among others, are natural insect repellents. Keep these plants in your home and garden for prevention.
• Identify the first signs of danger: check the soil, stalks and leaves well to see if there are any black ants. If there are, you will be able to detect if there aphids on your plants early.
• Find out about your plants: know what your plants are, how to look after them, the nutrients and fertiliser they need, and any useful tips to keep them healthy and prevent any attacks by pests.
• Find out about aphid predators: some species such as ladybirds are very effective in keeping aphids away. Knowing about aphids’ worst enemies will help you protect your plants.

Now you know that aphids are a common pest on our plants, you also know some easy ways to control them if you act in time. With information, prevention and perseverance you will be able to keep aphids at bay and enjoy a healthy, pest-free garden.