Holes in the leaves of plants and how to deal with them

All plants can develop holes in their leaves at some point.

Usually, the first thing we think when we see holes in plant leaves is that some insect or caterpillar is around and eating the leaves leaving bite marks.

There are, of course, plants such as monstera, where the morphology and configuration of their leaves includes normal characteristic holes.

For the rest, however, the holes that appear from external plant factors can be a significant problem, because they reduce the photosynthetic surface and make it difficult for them to grow lush vegetation.

Gradually and as the problem expands, due to the reduced metabolism of the plants, the ornamental plants show reduced flowering, while in fruit trees and horticultural trees a reduced fruit production is observed.

As part of proper plant care, it is important to observe our plants regularly, in order to detect the appearance of holes in the leaves in time, to identify the cause that causes them and to be able to protect them properly.

In today’s article, we will analyze the causes that can cause holes in the the leaves of the plants and we will see in what ways we can deal with them to protect our plants in ecological ways.

Why do holes appear in the leaves and how can we protect our plants?

Holes in plant leaves are due to three main causes: a) infestation by insects and caterpillars, b) infestation by fungal diseases and c) infestation by snails.

1. Holes in leaves caused by insects and caterpillars. In several vegetables, such as in the tomato crop, in the pepper crop, in the eggplant crop, as well as in cabbages, broccoli and cauliflower, we can see holes in the leaves, which are caused by insect caterpillars. Caterpillars are insects that hatch and eat the tender vegetation of our plants. There are many types of caterpillars, with different sizes and colors. Particularly well-known is the attack of the caterpillar on the rose bushes, which creates characteristic food spots. Also, insects such as mealybugs and stink bugs occasionally cause holes in the leaves of many vegetables, aromatic plants and ornamental plants. To deal with the caterpillars we use Thuringia bacillus, an organic preparation that can be obtained from agricultural stores, either in powder form for dusting, or in water-soluble form to spray the plants. We can also use natural pyrethrum, a biological preparation that is also used to treat stink bugs. To deal with the mealybug, we spray with an organic preparation of potassium salts. Alternatively, in cases of mild infestation and for preventive use, we can spray our plants with an improvised preparation that we make by dissolving 1 tablespoon of grated green in a liter of water.
2. Holes in the leaves caused by fungal diseases. In addition to caterpillars and insects, there are various fungal diseases that cause characteristic small holes in horticultural, ornamental and fruit trees. Such diseases are late blight, mange, rust and downy mildew. in the case of fungal diseases, initially, spots appear on the leaves which gradually dry up resulting in holes falling on the leaves. A typical example is the “shrapnel holes” that appear in the leaves of apricot, peach, plum and cherry when they are attacked by the leaf beetle, as well as the holes in the leaves of beet and of sedges when affected by the late blight fungus. For the preventive treatment of fungal diseases affecting fruit trees and sprayed on the leaves, with wet sulfur and copper in late winter, before the new vegetation opens, when the buds swell. More generally, to deal with fungal diseases, both in fruit trees and horticultural ones, we carry out preventive spraying with wet sulfur and copper on the foliage of the plants in the spring season, in order to prevent the appearance of infestations.
3. Snail holes in leaves. Snails and slugs make holes in the leaves of vegetables and herbs such as cabbage, spinach, arugula, lettuce, basil and many others. Often, the presence of snails is not easily noticed, because they move around at night when there is enough moisture. The nighttime humidity as well as the rain helps the snails to move and select our plants to feed on their foliage. If we look closely, we will notice the traces that leave a shiny slimy substance on the leaves. An ecological and highly effective way to deal with snails in the garden is by using ash. We throw the ash at a distance of 10 cm around the vegetables or parallel to the planting line to create a natural “wall”. Snails cannot move on the ash and thus do not get close to our plants. The ash is gradually washed away by rain and wind and frequent reapplication is required for best results.

And a secret about the holes in the leaves of plants. Another insect that can create leaf eaters is grasshoppers. For grasshopper prevention, dissolve 5 tablespoons of cayenne pepper in a container with half water and mix. Leave the medicine for 12 hours, strain it and then add 2 tablespoons of grated green soap. We spray our plants at dusk to avoid burns from the strong sunlight and the causticity of the solution.