Translated by Nick R
Are the leaves of your plants nibbled or full of holes? Are your plants not growing and getting weaker? Every gardener faces pest problems from time to time and learning how to deal with small threats is an essential step in growing a healthy, productive garden.
Below, you’ll find a list of the 9 most common pests that could come to your garden or home vegetable garden, but more importantly, you’ll learn how to identify them and, when the time comes, how to control them. Additionally, we’ll show you what measures you can adopt to prevent these undesirable insects.
Table of Contents
What are pests?
Gardens are living ecosystems with a wide variety of living organisms. Mostly, this rich abundance of life is good news for our gardens.
However, for an insect to be considered a pest has to cause a meaningful amount of damage. Although many insects eat plants, most of them do not cause major harm or, in most cases, the damage caused by these insects is not life-threatening to the plant.
In this sense, a pest is a living organism that devours and kills plants and crops. Thus, pests are responsible for two forms of crop damage.
First, there is some direct damage to plants when they feed on their tissues. This results in the withering of shoots and branches, reduced growth and reduced plant vigor through leaf damage or sap extraction.
Secondly, indirect damage occurs when pests do little direct damage, but spread or allow the entry of fungal, bacterial or viral infections. This results in dwarfing, deformation and stunting or diseases transmitted from one plant to another.
How to prevent them?
- Work with nature by creating a diversity of plant life. Mix flowers with vegetables to attract beneficial wildlife, such as caterpillar-eating birds and insects, such as ladybugs, that eat aphids.
- Choose plants and varieties that are suited to the location and soil type of your garden or orchard. Plants that struggle to grow will be weak and vulnerable to pests and diseases. You will be able to identify it according to its texture: Sandy, it is rough, dry to the touch and doesn’t retain water well. Loamy, it is dark brown, softer to the touch and holds water and nutrients better. Finally, clayey, with fine yellow grains, retains so much water that it even forms puddles.
- Before buying them from a nursery, inspect all new plants carefully. This will help you to avoid all of the insects that will appear in this guide to garden and vegetable garden pests.
- Space plants apart so that there is good airflow around them. Crowded plants trap moisture and encourage disease.
- Finally, remember that proper watering, the proper amount of light and good quality soil are essential for a healthy plant.
What are the most common pests?
It is important that you properly identify the most common garden pests, their characteristics and how much damage they can cause. Then you’ll know what measures to adopt to avoid them.
Red Spider Mite or Two-spotted Spider Mite
It’s a tiny but persistent and incredibly damaging insect. The spider mite is a mite that propagates quickly from one plant to another, thanks to its rapid life cycle and webbing.
Spider mites feed on the contents of plant cells, which makes them a dangerous enemy. In addition, they reproduce easily thanks to their ability to produce up to 300 eggs in just a few weeks.
You will notice when your plants are being attacked by spider mites if you observe these symptoms:
- White dots on the leaf surface. You will see many small white dots that are actually the eggs and mites sucking the plant’s sap.
- Fine spider webs along with the plant. It will look like thin silk that gradually spreads and covers the plant. This keeps the plant from getting good sun, which increases the problem even more.
- Dry leaves and early leaf drop. As we will see with other pests, large infestations can cause plants to weaken drastically and eventually die, unless they are quickly treated.
How to control spider mites
If you want to mitigate or control spider mite, you need to implement some of the following steps:
Increase humidity. This mite likes dry conditions, so keep your plants well-watered. As an additional option you can use your hose or watering can, with the nozzle at maximum pressure, to flush out the spiders.
Prune infected leaves, stems and branches. If you see that the life of the plant is not threatened, you can remove the infected plant material and discard it to prevent propagation. Likewise, if some leaves have already fallen, be sure to burn them.
Attract natural predators. Flowers will attract insects that help to remove certain pests naturally. One of the most effective predators is the ladybug, which will be very useful in your garden or vegetable garden. To attract ladybugs we recommend having marigolds, daisies, geraniums, mint or parsley.
Slugs and snails
Slugs are mollusks like snails, but with no shells. Both have a soft body and secrete slime as they move. They have rough tongues called radulae, which have microscopic tooth-like structures. These radulae break food into small pieces and cause a lot of damage to plants and crops.
Both slugs and snails feed mainly at night and can be gray, black, brown or even orange-colored. They eat a wide variety of vegetables and ornamental plants. They feed on leaves, stems, roots and tubers. Thus, potatoes, lettuce and celery are at considerable risk.
You might wonder how to recognize the slugs or snails, so here are the symptoms:
- Irregular holes in leaves. Their rough tongues create circular, uneven holes in whatever they have been eating. They especially like to devour seedlings or young plants; they are their favorite.
- Slime trails. They can leave silvery trails on leaves, stems, soil and surfaces as they use mucus or slime to aid their movement.
How to control slugs and snails
Alright, now let’s get on to how to control slugs and snails. We’ll share a few tips with you:
Use beer traps. You’ll be able to catch them easily, just sink a glass or container with beer into the soil, near the vulnerable plants. Both will be attracted by the smell of beer, fall down and drown. Remember to check traps regularly, as rotting slugs and snails will inevitably attract more of their kind to your garden.
Catch them manually. For this, you will need to go out into the garden at night with a flashlight and manually remove them from your plants, you can get rid of them at will. If you prefer not to kill them, be sure to carry them to a place away from other gardens.
Create barriers around your plants. Slugs and snails don’t like to crawl on certain textures and strong-smelling substances. Therefore, eggshells and coffee grounds (also known as sediment or used coffee) are ideal for protecting plants. Also, placing copper tape or other items with copper will help keep these little creatures away by giving them a slight static charge.
Cochinae – Mealybugs
These are white, cottony-looking insects, which is why they are also known as cottony mealybugs. They are quite mobile during their growing phase, but as they reach maturity and develop their rough, carapace-like armor, they become sedentary.
Mealybugs are found on a wide range of plants, and those found in warm conditions, such as houseplants and greenhouse plants, are particularly at risk. Outdoors, though, they can be found on ornamental plants, fruit trees, and shrubs.
You will recognize the presence of mealybugs on your plants from the following symptoms:
- Fuzz between the plant’s joints. One of the biggest inconveniences at the moment of detecting it is that this pest usually appears in the leaf joints and on the back of these, which makes it hard to see with the naked eye.
- The appearance of yellow spots on leaves. Also, reduced plant natural growth and deformation of the stem, branches and leaves.
- They attract other pests like ants. Due to the honeydew, a sugary substance, ants quickly arrive at the plant. In a way, to provide protection for the host pest.
How to control mealybugs
Okay, now we’ll show you how to deal with the mealybug:
Quarantine infected plants. This is to prevent the spread of mealybug to nearby plants. So keep the infected ones apart until you solve the problem.
Use this home remedy. You’ll only need 3 ingredients: Baking soda, vegetable oil and any kind of vinegar. What you should do is mix them in equal amounts and apply the mixture directly to the pest, you can help yourself with a cotton ball or a cloth. In the morning or at night, spread the mixture all over the plant, not forgetting the leaves’ backs. You’ll notice that in approximately 5 hours the mealybug will have died or fallen off the plant. If you have a large infestation, you can repeat the procedure for a couple of days.
Remove the mealybugs manually. If the infestation is just beginning, you can easily get rid of them by hand removal. Another option is to prune the affected stems and branches to minimize the problem.
Japanese rhinoceros (horned) beetle
These destructive Garden beetles feed on plants during both stages of their life cycle, from larvae to adulthood.
Generally, plants can withstand the harm caused by adult beetles. Of course, they won’t look aesthetically pleasing, but it doesn’t usually cause plants to lose their strength. It is the larvae, which live underground and eat the roots, stems and tubers, that cause the most serious damage, including the death of the plant.
If your plants are under attack from Japanese beetles, you will witness these symptoms:
- “Skeletal” leaves with many holes inside. The damage begins with small holes on the leaves and as they continue to feed, the leaf lamina or pulp gets removed and only the veins remain.
- Brown lawn. Since the larvae feed primarily on the roots, they’ll be responsible for causing several lawn areas to dry up or die. A noticeable damage to your garden.
- Plant odor. Sometimes, you can identify the presence of this pest because of an unpleasant odor produced by the excrement of its larvae.
How to control beetles
In case you want to learn how to deal with beetles, we suggest the following options:
Remove them manually. You can look for adult beetles in the leaf undersides and remove them yourself. You can also check around the roots, where most likely you’ll find semi-transparent white larvae with dark heads, and remove them.
Prune infected leaves and branches. Beetle attacks can make the plant look pitiful as if it were naked. So, if possible, remove those injured leaves and branches to give the plant a chance to recover.
Remove weeds regularly. Larvae also love certain types of weeds, so staying alert to weeding helps to limit their spread.
Whiteflies are very small, white insects. Despite their name, they are not a type of fly, although they have wings and are capable of flying. They usually cluster on the underside of leaves and disperse when the plant gets touched, making them easy to spot.
They can be found on a wide variety of plants, from ornamental flowers to warm-weather vegetables, including tomatoes, eggplants and paprika. They also like indoor plants, especially those with soft and smooth leaves.
If your houseplants are being attacked by whiteflies, you’ll see the following symptoms:
- Leaves with a sticky substance. Like aphids, whiteflies use their piercing mouthparts to suck plant juice and produce a sticky substance known as honeydew. The honeydew leaves plants vulnerable to fungi and other diseases.
- Weak plants with pale or yellow leaves. Because of whitefly feeding, plants wilt quickly and struggle to photosynthesize, causing growth to stop and leaves to drop.
How to control whiteflies
You’ll be able to control whitefly infestations with these tips:
Wash the plants with a strong water stream. This will help you remove those pesky insects, and especially the eggs. Recently laid whitefly eggs are pale yellow and when they are about to hatch their color changes to brown. If possible, submerge the plant in a bucket of water.
Spray the leaves with water and soap. This will also work for other pests and it is a simple mixture of water and dish soap. Make sure to apply it on the bottom of the leaves and preferably at night, when the temperature is cooler. No need to wash it off, it will not affect your plants.
Use monochromatic traps. All you have to do is get pieces of cardboard and paint them yellow. Afterward, you need to apply some kind of glue or adhesive plastic and place the traps in strategic spots in your garden. This way, whiteflies and other pests will stay away from your plants.
Caterpillars are soft larvae of different colors and sizes. As part of their life cycle butterflies lay eggs on plants and in a short time the caterpillars will hatch. Caterpillars can be found on many fruits and vegetables, ornamental plants and shade trees.
Clearly, caterpillars have the urge to feed in order to grow into large beautiful butterflies, but it is precisely because of their strong appetite that they are one of the most common and damaging pests.
These are the symptoms that a plant has caterpillars on it.
- Leaves with holes, particularly on the edges. You probably know that caterpillars love to chew on leaves and their edges. They also tend to dig tunnels in fruits.
- Black spot accumulation on leaves. That’s because they are the caterpillars’ feces. A clear sign that your plants are being visited by this pest.
How to control caterpillars
Now, we will tell you how to get rid of caterpillars:
Remove them manually. Thanks to their size, you will be able to identify and remove them quickly with your own hands in just a couple of seconds. Be sure to remove the eggs before they hatch too.
Apply protection to your plants. Mix equal amounts of baking soda and flour, depending on how many plants you will cover. Then, apply it directly to the leaves and spread it generating a protective layer. This way you will take care of your plants by preventing caterpillars to eat them.
Attract natural predators. You can place plants that have already shown symptoms near aromatic plants such as basil, mint and peppermint. Their powerful scent will attract wasps, which will eliminate the caterpillars.
Aphids are tiny, approximately 6 millimeters long. According to experts, they are pear-shaped and have long antennae. There are approximately 5,000 different species, but the most common are light green, white, gray or even pink. They are usually found on most fruits and vegetables, flowers, ornamental plants and shade trees.
These insects suck plant sap, causing foliage to deform and drop. They tend to cluster at the end of new growing shoots and attach themselves to soft, green stems.
If you have an aphid plague, you will notice the following symptoms:
- Deformed, stunted, yellowed leaves or loss of leaves, will surely weaken the plant.
- Leaves or stems are covered with a sticky substance. This is honeydew, a sugary liquid released by these insects when they feed on the sap. This can attract other insects, such as ants, which feed on this substance.
- Dark leaves and branches with black mold. Honeydew can also promote the appearance and growth of fumagine fungi or other diseases.
- Deformed flowers or fruit. This is also caused by aphid feeding.
How to control aphids
Now you may be wondering how to minimize or control aphid infections. Here are some methods you can use:
Wash the plants with a strong water stream. You can easily eliminate aphids by using your hose or watering can, preferably adjusting the nozzle so that the water comes out precisely to flush them out. This will usually prevent them from finding their way back to the plant.
Dust plants with flour. Another option is to place flour on infected plants, especially when you have a large aphid invasion. This will prevent them from feeding and causing more damage.
Spray the leaves with soap and water. You can get rid of aphids by wiping or spraying a soft solution of water and a few drops of dish soap. This mixture should be reapplied with soapy water every 2 to 3 days for 2 weeks. You may also purchase commercially available insecticidal soaps.
They are reddish-brown insects with tail pincers, measuring up to 2 centimeters in length. They can run very fast and are able to fly, although they rarely do it. Earwigs can be found in almost any growing area, but are more likely to be found in warm, humid climates.
They can be a nuisance for your garden, as they damage the petals of flowers such as dahlias, clematis, pansies and chrysanthemums. They are also fond of lettuce, celery and fruits.
However, earwigs also play an important role in the garden as they feed on aphids, insect eggs, worms and grubs. This is why earwigs generally do not cause enough damage to make them worth fighting.
Still, if you see a large number of them surrounding your plants, you may notice the following symptoms:
- Leaves, flowers and fruit with holes in them. Like slugs, earwigs feed and leave large, irregular holes. What will help you to distinguish them will be the lack of slime or lack of flax traces.
- Foul odor when disturbed. Several species give off and shoot a protective fluid. Its unpleasant odor helps them to defend themselves when they feel threatened.
How to control earwigs
You might consider taking these steps to eliminate earwigs from your garden:
Place petroleum jelly around the stems. This will prevent earwigs from crawling on them, which at the same time will stop them from getting to the leaves, in most cases.
Create an oil trap. Combine equal parts of soy sauce and olive or vegetable oil, place it in a small plastic container and close the lid tightly. In the top of the container, poke holes large enough for earwigs to fit through; then you’ll need to bury the container in the ground just up to the holes. The soy sauce will attract them while the oil will keep the earwigs from escaping.
Don’t get dispirited!
Throughout this guide, you got a better idea about possible pests that can reach your garden. So, when the time comes and you see your plants hurt, don’t get discouraged and take action.
Besides, keep in mind that all pest cases can be treated with insecticides or similar chemical products, which you can easily find in stores. This time, we wanted to give you more natural options that won’t have side effects on your beloved plants.