The winter-blooming Kalanchoe may suffer from diseases related to improper care or the attack of pathogenic organisms. Usually, the owners of these flowers are disturbed by symptoms such asyellow Kalanchoe leaves , disfiguring the plantstains on the Kalanchoe leavesorwhite bloom covering various parts of the plant. Seehow to fight kalanchoe diseases , what to look for when caring for plants and what to do to make the kalanchoe look beautiful again.
Kalanchoe diseases - leaf spot
Kalanchoe diseases - yellow leaves
Yellowing of Kalanchoe leavesis most often caused by over-watering, leading to flooding of the roots. In this case, watering should be limited, especially in winter, and the soil should be allowed to dry out. Kalanchoe does not require a lot of water. It is enough to moisten the soil once every 10-14 days. Remove the water accumulated on the stand after 15 minutes so that the plant does not stand in the water.We don't water the Kalanchoe when the leaves are hangingbecause that means the ground is too wet, not too dry as many people mistakenly believe.
Adequate drainage in the pot should also be provided. At the bottom of the container in which we will grow kalanchoe, sprinkle about 2 cm with a layer of pebbles, expanded clay or crushed ceramics. This will facilitate the drainage of the water, while preventing it from remaining in the area of the Kalanchoe roots.
Uneven watering, i.e. long periods of drought and then pouring a large amount of water in the stand, alsoleads to yellowing of the Kalanchoe leaves If we cannot provide our Kalanchoe with regular watering, we should opt for hydroponic cultivation. Special pots for this purpose are equipped with water tanks, which the plant uses when needed. Installed water level indicators inform us when it should be refilled.
Anothercause of yellowing Kalanchoeleaves may be the plant's exposure to ethylene. Ethylene is a gas found in cigarette smoke and exhaust fumes, and it is also emitted by ripening fruit (especially apples). The solution is to take the Kalanchoe pot out of the smoking room or the kitchen where the fruit is kept.
The lack of minerals in the substrate may alsomanifest itself in the yellowing of Kalanchoe leavesKalanchoe is particularly sensitive to zinc deficiency in the soil. When this component is missing, the leaves turn yellow between the veins, lose their vigor and distort. To prevent zinc deficiency, Kalanchoe should be grown in a substrate with a pH of 6.0-6.5, rich in peat and perlite.Florists offer ready-made mixes for growing cacti and succulents that will suit your needs.
Kalanchoe diseases - spots on leaves
1. Kalanchoe leaf corkiness
Convex, light brown spots on the underside of the Kalanchoeleaves indicate a physiological disease - Kalanchoe leaf corkiness. It results from the cultivation of Kalanchoe in conditions of high temperature (25 ° C and more) and increased air humidity. Under such conditions, the Kalanchoe retains water in its tissues and reduces transpiration (water vapor excretion through the stomata). The cells of the crumb fill with water and swell. After some time, the water-swollen cell explodes, causing numerous, convex, light brown spots to appear on the underside of the leaf.Kalanchoe leaf corkinessgenerally does not adversely affect plant he alth, but may significantly reduce its attractiveness.
To prevent such damage, do not spray the plant.In summer, the premises where we grow kalanchoe should be well ventilated. On the windowsill, the leaves of the kalanchoe should not come into contact with the leaves of neighboring plants, especially with those that are sprinkled and frequently watered, such as the perennial or aglaonema.
2. Kalanchoe leaf spot
Ifon both sides of the Kalanchoe leaves there are very numerous tiny (1-3 mm), initially yellow spots , which turn brown over time, this may indicate an infestation by Kalanchoe leaf blotch. It iskalanchoefungal disease, caused by the fungus Stemphylium bolickii.
The stains observed usually do not increase in size for a very long time. Sometimes, however, they merge with each other and cover a large part of the surface of the upper and lower sides of the leaf. InfestedKalanchoe leaves gradually turn yellow and fall offThe fungus continues to develop on fallen leaves. Spores develop in places of brown spots, which are transmitted by water droplets (e.g.while watering) or insects on neighboring plants.
The development of Kalanchoe leaf blotch is favored by moisture , so avoid soaking the Kalanchoe leaves during watering. Water drops on leaves should be removed with a dry cloth. Place the Kalanchoe pot in a ventilated place. Fallen leaves with symptoms of the disease should be removed and destroyed. Spray the remaining parts of the plant 1-2 times with Biosept Active (dilute 0.1 ml of the preparation in 200 ml of water) or Bioczos (5 ml / 250 ml of water). In case of severe infection, spray with a fungicide - Topsin M 500 SC (0.5 ml / 250 ml of water), Dithane NeoTec 75 WG (0.5 ml / 250 ml of water) or Domark 100 EC (0.25 ml / 250 ml of water)
3. Gray mold kalanchoe
Gray mold, caused by the fungus Botrytis cinerea, is one of the most common fungal diseases in indoor plants. It attacks leaves, stems and flowers. Weakened or overfertilized plants are extremely susceptible to gray mold infection.
The most characteristic symptom isa dusty grayish coating of mycelium and spores on dying parts of the kalanchoeBefore the appearance of the mycelium coatingwatery brown spots form at the base of the kalanchoe shoots Part of the rush above the site of infection dies.
Gray mold grows where there is high air humidity. Therefore, avoid wetting the leaves when watering. Fallen leaves and flowers should be systematically removed from the ground in a pot, especially when it is constantly wet. It is plant debris that decomposes in a humid environment that is the source of infection. It is necessary to limit the watering of the kalanchoe, especially in winter? once every 2 weeks is enough. In winter, it is recommended to water the Kalanchoe in the morning so that during the day the parts of the plant moistened with watering have time to dry. This is important as the fungus grows at night.
Infested with gray Kalanchoe moldSpray twice (10 days apart) with the following preparations: Teldor 500 SC (0.25 ml / 250 ml of water), Kaptan suspension 50 WP ( 0.5 g / 250 ml of water), Miedzian 50 WP (0.6 g / 250 ml of water) or Biosept (0.1 ml / 200 ml of water).
Kalanchoe diseases - white coating on leaves
1. Kalanchoe powdery mildew
Powdery mildew is a common fungal disease in many plants. It thrives in warm (21 ° C) and humid conditions. The symptom of powdery mildew iswhite, powdery coating covering the leaves and twigs of kalanchoeAfter lowering the humidity and the temperature above 20 ° C, the white mycelium disappears and brown spots of dead tissue appear in its place.Kalanchoe leaves curl, dry out and die.Kalanchoe flowers are distorted or the plant does not bloom at all. Thiskalanchoefungal disease can spread to other plants growing nearby by wind or water that is splashed with careless watering.
We can prevent powdery mildew by making sure thatthere is no water on the Kalanchoe leavesWhen watering, try to pour water directly onto the substrate so as not to wet the leaves and stems.We should ensure good air exchange between plants and avoid crowding them, for example, on the windowsill, thanks to which the wet Kalanchoe leaves will be able to dry quickly enough. When we noticemildew symptoms on kalanchoewe spray all parts of the plant 3-4 times every 7-10 days with alternating fungicides. Recommended fungicides forto combat powdery mildew Kalanchoeare: Domark 100 EC (0.25 ml / 250 ml water), Substral Long Acting Saprol (3.75 ml / 250 ml water) and Substral Flowers Comprehensive Protection (5 ml / 250 ml of water). Alternatively, you can use Biosept (0.1 ml / 200 ml of water) and Bioczos (5 ml / 250 ml of water) for spraying.
2. Wełnowce
Mealybugs are common pests of houseplants. The most common is the citrus mealybug (Planococcus citri), which has a very wide range of host plants. It happens that it also inhabits kalanchoe.
Mealybugs are small (2-5 mm) insects with a flat, oval and soft body.Their body is segmented and covered with white waxy scales. They feed on the shoots and the underside of the Kalanchoe leaves. They cause the weakening of the plant, yellowing of the leaves, inhibition of growth and stunting of the shoots. Foraging, they contaminate the leaves with a white woolly or powdery coating that looks like cotton wool clumps. Like aphids and whiteflies, mealybugs secrete honeydew, which becomes a breeding ground for fungi.
Fighting mealybugs on kalanchoeis not difficult. We remove them mechanically from the leaves with a brush released with denatured alcohol. You can also pick them up with a toothbrush and then wipe the leaves and shoots of the Kalanchoe with a cotton pad soaked in water and gray soap. Another way toget rid of the mealybug from Kalanchoe leavesis to spray it with rapeseed oil. Can we quickly prepare such a preparation in our own kitchen? Dilute 5 ml of rapeseed oil in 250 ml of water (1 glass), we can add 2 drops of gray liquid soap to the solution so that the preparation sticks to the leaf surface and does not drain off too quickly.We spray 3 times with an interval of 1-2 days.
Remember!After spraying, place the Kalanchoe pot in a ventilated place so that the leaves dry quickly and no water drops are left on them.
MSc Eng. Agnieszka Lach
