When the red spider attacks ornamental plants the first thing to do is to increase the humidity level. This mite, which is also an arachnid, does not like water and with frequent foliar irrigation it could go away spontaneously. Even better if you can do the complete washing of the leaf (using cotton wool or a soft cloth soaked in water), which is not impossible with many ornaments.
The limit of this 'first aid' intervention is that the water eliminates the adults of red spider but not the eggs, which hatch in summer. If the infestation is far from the moment of hatching and timely intervention, water and greater humidity can solve the problem. But if the colony has already 'put up the tents', something stronger is needed.
Red spider mite and ornamental plants: natural remedies
If you don't want to use harsh chemicals, at least not right away, you can fight the red spider with applications of lithotamnium powder or rock flour. The latter is found quite easily in specialized shops: it is industrially produced from quarry waste (in practice it is a by-product of stone processing) such as basalt, granite and lava and is a valid alternative to chemicals in the fight against many plant parasites .
Red spider mite and ornamental plants: chemical remedies
The active ingredient that works best against the red spider mites of ornamental plants is Bifenazate, a biodegradable substance marketed in some products, the best known of which is Floramite. It is necessary to dilute it with water and spray all over the plant, thus also increasing the humidity rate. Generally the first intervention consists of two applications spaced one week apart. Then the treatment is checked and if necessary the treatment is repeated. Do not overdo it with chemicals and use only specific ones (possibly get advice). There is a risk not only of damaging the plants, but also of exterminating those natural predators of the red spider that could be useful instead.
You might be interested in the article "Red spider: remedies to remove it”
If you are looking for a specific product ready to use (no need to dilute) against the red spider on the ornaments, I recommend Mighty Wash