Orchids are one of the families of ornamental plants preferred by people to grow. The beauty of this group of plants lies in its great variety of shapes and striking colors. However, like any plant, they are also exposed to different pests and diseases caused by insects, bacteria, viruses or fungi.
When treating these diseases, we can help ourselves with products such as insecticides, bactericides or fungicides, both commercial and homemade. We will focus on homemade fungicides for orchids and which are the most common fungi in orchids.
Main fungi in orchids
Fungi are one of the main threats to orchids, but we can combat them successfully if we detect them in time. They usually look like dark spots on leaves and flowers. They can also be detected as changes in the color of the leaves towards more brown, black or gray tones, depending on the conditions and the type of plant.
The appearance of fungi on plants is facilitated by excess humidity or water retention, high temperatures and poor ventilation. Some of the most common fungi in orchids are:
Black rot of leaves, pseudobulbs or roots (Black Rot)
The fungus that causes these diseases belongs to Phytophthora sp. or Pythium sp. and it manifests as a blackish spot surrounded by a yellowish halo in almost all parts of the plant (with the exception of the flowers). Once the disease progresses to the pseudobulbs or roots, it can lead to death. In addition to high humidity, it is also spread by the use of poorly disinfected tools or open wounds.
Flower and leaf rot
These infections are mostly due to the fungus Botrytis spp. This fungus attacks both flowers and leaves. These infections are easily recognizable, since the attacked tissues become soft and oval or round spots form on the petals.
The fungus that causes this disease is Glomerella spp. It is characterized by the presence in the aerial parts of the plant of rounded and depressed dark spots, which are separated by healthy parts.
They are produced by the fungus Fusarium spp. and it is characterized by producing irregular black spots that converge to form necrotic areas on the leaves. This disease can produce a growth arrest of the plant.
Homemade fungicides for orchids
Although we can prevent the appearance of fungi in our orchids by promoting ventilation or disinfecting work tools, once the fungi appear, it is possible to treat them by applying fungicides. Many of these fungicides can be made from substances that are used everyday at home. Some examples of homemade fungicides for orchids are:
Cinnamon is one of the common products in the kitchen or that we can easily get. To treat infections, we can use it as a powder or make a paste with glue, which consists of mixing cinnamon powder with liquid white glue to form a thick, brown paste. An alternative to using glue is cooking oil, although in this case you have to use more cinnamon.
This is another one of the best homemade fungicides for orchids. It consists of placing a cup of cornmeal in boiled water. Let it sit for a couple of days and spray it to use as a spray.
Garlic is used to control fungi due to its high sulfur content. The preparation consists of liquefying 5 to 10 garlic cloves in half a liter of water. Then we will filter and macerate the mixture for 1 hour, before applying it. It can also be applied every 15 days.
Sodium bicarbonate as a fungicide is very useful, because it manages to raise the pH of the medium. The preparation consists of mixing a tablespoon of baking soda in a liter of water. Then, we will add a splash of soap and another of oil and we can apply it on the plant. The mixture should be applied every week and after the rainy seasons.
Vinegar is another common element in kitchens. Its effect against fungi is similar to that of bicarbonate, only instead of raising the pH, it lowers it. The preparation consists of mixing a tablespoon of vinegar in a liter of water and applying it twice a week, after the rains.
How to add cinnamon to orchids
We have already commented on it in the previous section, but it is worth making a paragraph to explain in more depth the method of cinnamon as a fungicide for orchids, among other things, because it is one of the most used.
The method of applying cinnamon to our orchids depends on its shape. If it is cinnamon powder, we will apply it directly on the infected area. If, on the other hand, it is cinnamon paste made with glue or any other substance, we will spread the paste well on the site of the infection. White glue, although it is soluble in water, withstands waterings well, so there is no problem in applying it to those orchids where it is watered frequently.