The sage diseases, their symptoms and how they are treated. Here how sage is treated.
The possible sage diseases there are so many to question the very name 'sage', which derives from the Latin salus and it means health. Naturally, nature has given this plant extraordinary medicinal properties, but it has not made it the strongest and most resistant.
Diseases of the sage
The sage diseases they certainly do not prevent the cultivation of this widespread perennial suffruticosa, only they recommend some attention if you want to better appreciate its aromatic and medicinal properties.
So let's see which are the most frequent sage diseases, how they are recognized in a timely manner and how they can be addressed. Let's start with the symptoms.
White or brown powder on the leaves
It means that the sage has been affected by the white disease (or powdery mildew), a fungus that is not dangerous but to be countered immediately. Infestation occurs both on the upper and lower side of the leaves, more frequently at the end of summer.
How to fight. consists in detaching the attached parts as soon as possible and, having done this, other treatments may not be needed. If the problem persists, horsetail decoction (spray on the leaves) and possibly a sulfur-based treatment can be used, but only if the attack is heavy.
Black spots on sage leaves
This is downy mildew, another fungus, but more dangerous than the white sickness. The black spots appear on the upper side of the leaves and correspond, on the underside, to a white powdery mold. Affected leaves shorten, dry out and fall off.
How to fight. At the first symptoms, and as a prevention on young plants, nettle macerate is useful. When the infestation is in progress, copper-based products are used, generally with 2-3 treatments spaced 10 days apart.
The leaves curl up and white cobwebs appear
It means that the spider mite, a plant mite that feeds on sap, has taken home on your sage. The presence of whitish cobwebs on the underside of the leaves is a sign of an infestation already in an advanced stage.
How to fight. Unlike mushrooms, the red spider does not like humid environments and the first remedy consists in frequent foliar irrigations simply with water. If this first treatment is not enough, you can use lithotamnum powder or rock flour.
Theresageit is not immune to plant lice. If shaking the fronds you notice small white animals jumping from one area to another, the plant is infested with plant lice. In this case, a treatment with pyrethrum is strongly recommended.
White cobwebs and licethey can be counteracted by following the instructions seen in the article dedicated to plant mites.
Among the various pyrethrum-based products we point out one for its excellent value for money. This is the Solabiol Piretro Actigreen Bio, offered on Amazon at a price of 18.69 euros with free shipping costs. For all the info, I refer you to the official Amazon product page: Actigreen Bio Liquid solution. 14-25 ml of product are enough to be diluted in 10 liters of water and sprinkle on plants infested withmites, plant lice and other small parasites.
Warning! It should not be used in case of fungal diseases because it is ineffective.
Sage with yellow leaves
If thesage plantpresentsyellow leaves the causes can be many. To locate thesage diseasethat causes this problem, other symptoms can be evaluated.
Sage does not grow and has yellow leaves
The fault lies with radical rot, a term used to define some alterations of the root system. Among the fungal pathogens responsible for root rot, those that make sage are the Pythium splendens, which affects indoor plants in particular, and Rizocthonia violacea, which covers the roots of affected plants with a velvety red patina.
How to fight. The first thing to do is to repot the plants with new soil. The second is correct watering: Root rot, as well as fungal diseases, are almost always caused by stagnation of water. Only if the re-establishment of the correct conditions is not enough is intervention with fungicide products justified.
The leaves turn yellow and fall off
In this case, the problem may be caused by nematodes, small worms similar to an eel that penetrate the plant and take away vital substances. Related symptoms are also plant wasting, dwarfism and thickening of the leaf plate.
How to fight. For nematodes there is a very effective natural contrastant called marigold. Sow this essence in nematode-infested pots and flower beds and they will go away on their own.
Sage: plant care
Warning! With sage talking about an aromatic plant intended for use in the kitchen and in herbal medicine, therefore it must be remembered that chemical treatments should be limited to a minimum. Better to use products allowed in organic farming such as pyrethrum and other natural remedies.
If you use any product to counter a disease in progress, the precautions for use and the periods of distance from collection indicated by the individual products must be observed. In summary: read the label of the product used carefully.