A Complete Guide to Foliage Plant Pest and Disease Control
During their growth, foliage plants may be attacked by pests and diseases. Affected plants not only have their growth impaired, but also lose some or even all of their ornamental value. Therefore, pest and disease control for indoor foliage plants is essential, and it is a basic skill that every flower lover needs to master; otherwise, the true purpose of foliage plants in beautifying and purifying the environment is lost.
There are many kinds of indoor foliage plants, but for any given unit or household, the number used is rather small, and care tends to be fairly meticulous. If pests or diseases occur, they do not easily spread to other plants, but they often develop quickly on the affected plant. Therefore, pest and disease control for these plants should focus mainly on prevention, with integrated control, while strengthening cultivation management: creating a good plant ecological environment, promoting healthy plant growth, and improving the plants' own stress resistance, along with other effective cultivation measures.
All indoor foliage plants should undergo strict inspection before being brought indoors for display. Choose highly adaptable, disease-resistant varieties or healthy plants and arrange them sensibly. If slight diseased leaves or a small number of aphids, mites or scale insects are found, physical methods should be used promptly, such as manual pruning to remove diseased leaves, or washing with soapy water followed by a rinse with clean water or wiping with a soft damp cloth; scale insects can also be gently scraped off with a bamboo stick. If the infestation is severe, move the plant outdoors for treatment.
Pesticides should never be used indoors on indoor foliage plants, because insecticides are generally toxic substances, and if such toxic materials remain or are carried into the indoor air circulation system, they will lead to various adverse consequences. As ornaments, indoor foliage plants tend to invite people to admire their various characteristics; some may smell them, and some may touch their branches and leaves. In order to maintain good public relations, it should be stipulated that pesticides are not used to control pests and diseases on indoor decorative plants. If some plants are attacked by pests or diseases and physical methods cannot effectively control them, they must be moved outdoors, isolated from healthy indoor plants, and then given other treatment, such as chemical control, or destroyed. Plants brought indoors must be checked regularly, with timely treatment and control; this can reduce the degree of damage to plants and prevent trouble before it happens. Keeping the indoor environment clean and hygienic with good ventilation and light transmission will keep foliage plants green and fresh with high ornamental value.
Physical Control Methods
Below are some common pests and diseases of foliage plants, along with suggestions for indoor physical control methods:
(1) Aphids: these are common small, soft-bodied insects that often attack the growing tips and young leaves of plants such as begonias, ivy, bloodleaf (Iresine), and plants in the Araliaceae family. For control, wash the leaves with water or soapy water, or remove the affected parts.
(2) Mites: they mainly attack the leaves of plants such as Swiss cheese plant (Monstera deliciosa), croton (Codiaeum variegatum), philodendron (Philodendron), rubber plant (Ficus elastica) and inch plant (Tradescantia zebrina), spreading from the lower leaves upward, sucking nutrients from new buds and leaves and causing leaf discoloration. For control, sprinkle water on the leaf surface to wash off the mites. Plants with severe infestation should be moved away immediately.
(3) Scale insects: they often attack the branches and leaves of croton (Codiaeum variegatum), maranta (Maranta), dracaena (Dracaena) and bromeliads, and usually cluster on branches and leaves to suck nutrients. A hot, humid environment with poor ventilation and light transmission is a suitable condition for scale insects to flourish. Therefore, pay attention to strengthening ventilation and light transmission and improving indoor conditions. Scale insects spread very little on their own, so doing good quarantine work and not using insect-infested materials are the most effective control measures. If scale insect damage has already occurred, scrape the insects off with a bamboo stick or cut off the affected parts.
(4) Thrips: they attack the leaves of begonias, hyacinths and poinsettias, often damaging near the leaf stalks and veins and crawling on the leaf surface to suck nutrients, causing the leaves to lose their green color and vitality. If only a small number of plants are affected, wipe them off with an alcohol cotton swab or wash them with soapy water.
(5) Anthracnose: it attacks bromeliads, dracaena (Dracaena), croton (Codiaeum variegatum), pepperomia (Peperomia), rubber plant (Ficus elastica) and wax plant (Hoya) among others. It infects leaves and causes black spots on them. Control of this disease mainly involves strengthening management, maintaining good light transmission and ventilation, avoiding overhead watering and instead watering from the edge of the pot, and promptly cutting off diseased leaves if any are affected.
(6) Rust: it attacks the leaves of plants in the Rosaceae family and of the wax plant (Hoya). In the early stage, orange-red spots appear on the leaf surface, and later brown spores appear on the underside of the leaves. Control methods: disinfect the growing medium in advance, strengthen environmental management, maintain ventilation and light transmission, and remove diseased leaves when necessary.
(7) Brown spot: it attacks the leaves of dracaena (Dracaena), Swiss cheese plant (Monstera deliciosa) and palms. In the early stage of damage, small irregular brown spots appear on the leaf surface; later they turn grayish white and gradually dry, scorch and die. Control methods: manually prune diseased leaves and dead branches and burn them in a centralized manner.
(8) Soft rot: it attacks the leaves of wax plant (Hoya) and nerve plant (Fittonia). In the early stage, water-soaked spots appear on the leaf surface and leaf stalks, after which the plant wilts and droops, losing its ornamental value. For control, pay attention to meticulous management, avoid watering the leaf surface, and cut off the affected branches and leaves.
(9) Powdery mildew: it attacks plants in the Asteraceae and Rosaceae families, damaging the leaves. For control, pay attention to strengthening management, maintaining good ventilation and light transmission indoors, and cutting off diseased leaves.
Chemical Control Methods
If the physical control methods above are ineffective, the plant should be moved outdoors and then given chemical control. Common methods include:
(1) Spraying pesticides on the leaf surface: according to their different modes of action, pesticides can be divided into three types: systemic, contact, and protective/therapeutic. Among systemic types, insecticides include omethoate and others, mainly controlling scale insects, mites and aphids; fungicides include carbendazim, thiophanate-methyl and others, which are effective against leaf spot, anthracnose, brown spot and rust in plants. Contact insecticides include dichlorvos, pyrethroids and others, which can kill larvae with chewing mouthparts, aphids and newly hatched scale insects. Protective/therapeutic pesticides mainly form a film on the plant surface, thereby protecting, treating, or killing pests and diseases, such as lime sulfur mixture, sulfur suspension concentrate and polymer films.
(2) Applying pesticides to the soil: the active ingredients of such pesticides can be absorbed by plant roots and transmitted to all parts of the whole plant to kill pests and diseases on the leaves, or directly kill pests and diseases in the soil.
Pest and Disease Control for Foliage Plants
During their growth, foliage plants may be attacked by pests and diseases. Affected plants not only have their growth impaired, but also lose some or even all of their ornamental value. Therefore, pest and disease control for indoor foliage plants is essential, and it is a basic skill that every flower lover needs to master; otherwise, the true purpose of foliage plants in beautifying and purifying the environment is lost.
There are many kinds of indoor foliage plants, but for any given unit or household, the number used is rather small, and care tends to be fairly meticulous. If pests or diseases occur, they do not easily spread to other plants, but they often develop quickly on the affected plant. Therefore, pest and disease control for these plants should focus mainly on prevention, with integrated control, while strengthening cultivation management: creating a good plant ecological environment, promoting healthy plant growth, and improving the plants' own stress resistance, along with other effective cultivation measures.
All indoor foliage plants should undergo strict inspection before being brought indoors for display. Choose highly adaptable, disease-resistant varieties or healthy plants and arrange them sensibly. If slight diseased leaves or a small number of aphids, mites or scale insects are found, physical methods should be used promptly, such as manual pruning to remove diseased leaves, or washing with soapy water followed by a rinse with clean water or wiping with a soft damp cloth; scale insects can also be gently scraped off with a bamboo stick. If the infestation is severe, move the plant outdoors for treatment.
Pesticides should never be used indoors on indoor foliage plants, because insecticides are generally toxic substances, and if such toxic materials remain or are carried into the indoor air circulation system, they will lead to various adverse consequences. As ornaments, indoor foliage plants tend to invite people to admire their various characteristics; some may smell them, and some may touch their branches and leaves. In order to maintain good public relations, it should be stipulated that pesticides are not used to control pests and diseases on indoor decorative plants. If some plants are attacked by pests or diseases and physical methods cannot effectively control them, they must be moved outdoors, isolated from healthy indoor plants, and then given other treatment, such as chemical control, or destroyed. Plants brought indoors must be checked regularly, with timely treatment and control; this can reduce the degree of damage to plants and prevent trouble before it happens. Keeping the indoor environment clean and hygienic with good ventilation and light transmission will keep foliage plants green and fresh with high ornamental value.
1. Physical Control Methods
Below are some common pests and diseases of foliage plants, along with suggestions for indoor physical control methods:
(1) Aphids: these are common small, soft-bodied insects that often attack the growing tips and young leaves of plants such as begonias, ivy, bloodleaf (Iresine), and plants in the Araliaceae family. For control, wash the leaves with water or soapy water, or remove the affected parts.
(2) Mites: they mainly attack the leaves of plants such as Swiss cheese plant (Monstera deliciosa), croton (Codiaeum variegatum), philodendron (Philodendron), rubber plant (Ficus elastica) and inch plant (Tradescantia zebrina), spreading from the lower leaves upward, sucking nutrients from new buds and leaves and causing leaf discoloration. For control, sprinkle water on the leaf surface to wash off the mites. Plants with severe infestation should be moved away immediately.
(3) Scale insects: they often attack the branches and leaves of croton (Codiaeum variegatum), maranta (Maranta), dracaena (Dracaena) and bromeliads, and usually cluster on branches and leaves to suck nutrients. A hot, humid environment with poor ventilation and light transmission is a suitable condition for scale insects to flourish. Therefore, pay attention to strengthening ventilation and light transmission and improving indoor conditions. Scale insects spread very little on their own, so doing good quarantine work and not using insect-infested materials are the most effective control measures. If scale insect damage has already occurred, scrape the insects off with a bamboo stick or cut off the affected parts.
(4) Thrips: they attack the leaves of begonias, hyacinths and poinsettias, often damaging near the leaf stalks and veins and crawling on the leaf surface to suck nutrients, causing the leaves to lose their green color and vitality. If only a small number of plants are affected, wipe them off with an alcohol cotton swab or wash them with soapy water.
(5) Anthracnose: it attacks bromeliads, dracaena (Dracaena), croton (Codiaeum variegatum), pepperomia (Peperomia), rubber plant (Ficus elastica) and wax plant (Hoya) among others. It infects leaves and causes black spots on them. Control of this disease mainly involves strengthening management, maintaining good light transmission and ventilation, avoiding overhead watering and instead watering from the edge of the pot, and promptly cutting off diseased leaves if any are affected.
(6) Rust: it attacks the leaves of plants in the Rosaceae family and of the wax plant (Hoya). In the early stage, orange-red spots appear on the leaf surface, and later brown spores appear on the underside of the leaves. Control methods: disinfect the growing medium in advance, strengthen environmental management, maintain ventilation and light transmission, and remove diseased leaves when necessary.
(7) Brown spot: it attacks the leaves of dracaena (Dracaena), Swiss cheese plant (Monstera deliciosa) and palms. In the early stage of damage, small irregular brown spots appear on the leaf surface; later they turn grayish white and gradually dry, scorch and die. Control methods: manually prune diseased leaves and dead branches and burn them in a centralized manner.
(8) Soft rot: it attacks the leaves of wax plant (Hoya) and nerve plant (Fittonia). In the early stage, water-soaked spots appear on the leaf surface and leaf stalks, after which the plant wilts and droops, losing its ornamental value. For control, pay attention to meticulous management, avoid watering the leaf surface, and cut off the affected branches and leaves.
(9) Powdery mildew: it attacks plants in the Asteraceae and Rosaceae families, damaging the leaves. For control, pay attention to strengthening management, maintaining good ventilation and light transmission indoors, and cutting off diseased leaves.
2. Chemical Control Methods
If the physical control methods above are ineffective, the plant should be moved outdoors and then given chemical control. Common methods include:
(1) Spraying pesticides on the leaf surface: according to their different modes of action, pesticides can be divided into three types: systemic, contact, and protective/therapeutic. Among systemic types, insecticides include omethoate and others, mainly controlling scale insects, mites and aphids; fungicides include carbendazim, thiophanate-methyl and others, which are effective against leaf spot, anthracnose, brown spot and rust in plants. Contact insecticides include dichlorvos, pyrethroids and others, which can kill larvae with chewing mouthparts, aphids and newly hatched scale insects. Protective/therapeutic pesticides mainly form a film on the plant surface, thereby protecting, treating, or killing pests and diseases, such as lime sulfur mixture, sulfur suspension concentrate and polymer films.
(2) Applying pesticides to the soil: the active ingredients of such pesticides can be absorbed by plant roots and transmitted to all parts of the whole plant to kill pests and diseases on the leaves, or directly kill pests and diseases in the soil, such as formalin and other agents.
Physical Pest and Disease Control Methods for Foliage Plants
Some common pests and diseases of foliage plants, along with suggestions for indoor physical control methods:
(1) Aphids:these are common small, soft-bodied insects that often attack the growing tips and young leaves of plants such as begonias, ivy, bloodleaf (Iresine), and plants in the Araliaceae family. For control, wash the leaves with water or soapy water, or remove the affected parts.
(2) Mites:they mainly attack the leaves of plants such as Swiss cheese plant (Monstera deliciosa), croton (Codiaeum variegatum), philodendron (Philodendron), rubber plant (Ficus elastica) and inch plant (Tradescantia zebrina), spreading from the lower leaves upward, sucking nutrients from new buds and leaves and causing leaf discoloration. For control, sprinkle water on the leaf surface to wash off the mites. Plants with severe infestation should be moved away immediately.
(3) Scale insects:they often attack the branches and leaves of croton (Codiaeum variegatum), maranta (Maranta), dracaena (Dracaena) and bromeliads, and usually cluster on branches and leaves to suck nutrients. A hot, humid environment with poor ventilation and light transmission is a suitable condition for scale insects to flourish. Therefore, pay attention to strengthening ventilation and light transmission and improving indoor conditions. Scale insects spread very little on their own, so doing good quarantine work and not using insect-infested materials are the most effective control measures. If scale insect damage has already occurred, scrape the insects off with a bamboo stick or cut off the affected parts.
(4) Thrips:they attack the leaves of begonias, hyacinths and poinsettias, often damaging near the leaf stalks and veins and crawling on the leaf surface to suck nutrients, causing the leaves to lose their green color and vitality. If only a small number of plants are affected, wipe them off with an alcohol cotton swab or wash them with soapy water.
(5) Anthracnose:it attacks bromeliads, dracaena (Dracaena), croton (Codiaeum variegatum), pepperomia (Peperomia), rubber plant (Ficus elastica) and wax plant (Hoya) among others. It infects leaves and causes black spots on them. Control of this disease mainly involves strengthening management, maintaining good light transmission and ventilation, avoiding overhead watering and instead watering from the edge of the pot, and promptly cutting off diseased leaves if any are affected.
(6) Rust:it attacks the leaves of plants in the Rosaceae family and of the wax plant (Hoya). In the early stage, orange-red spots appear on the leaf surface, and later brown spores appear on the underside of the leaves. Control methods: disinfect the growing medium in advance, strengthen environmental management, maintain ventilation and light transmission, and remove diseased leaves when necessary.
(7) Brown spot:it attacks the leaves of dracaena (Dracaena), Swiss cheese plant (Monstera deliciosa) and palms. In the early stage of damage, small irregular brown spots appear on the leaf surface; later they turn grayish white and gradually dry, scorch and die. Control methods: manually prune diseased leaves and dead branches and burn them in a centralized manner.
(8) Soft rot:it attacks the leaves of wax plant (Hoya) and nerve plant (Fittonia). In the early stage, water-soaked spots appear on the leaf surface and leaf stalks, after which the plant wilts and droops, losing its ornamental value. For control, pay attention to meticulous management, avoid watering the leaf surface, and cut off the affected branches and leaves.
(9) Powdery mildew:it attacks plants in the Asteraceae and Rosaceae families, damaging the leaves. For control, pay attention to strengthening management, maintaining good ventilation and light transmission indoors, and cutting off diseased leaves.