Symptoms | Possible Causes | Control/Comments |
---|---|---|
Plant wilting |
Overwatering or lack of water: overwatering can cause root rots. Healthy roots should be light-colored and firm. |
Use a well-drained, soilless potting media labeled for houseplants. Water should be able to drain from the bottom of containers.
|
Plant wilting |
Various root rots: pull plant out of the pot and observe roots for discoloration. Diseased roots will appear dark and soft. |
Remove diseased plants from their pots, cut
|
Plant wilting |
Stem cankers: discolored areas on stem |
Prune out affected areas. |
Leaf yellowing, foliage fades, yellows browns or wilts |
Aphids: small soft-bodied insects found on leaves, stems and flower buds.
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Regularly rinse plants with water to keep down pest problems. Use a registered houseplant spray to control pests. Plants damaged by heavy insect or mite feeding can be injured by insecticidal sprays. Severely damaged plants should be discarded.
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Leaf yellowing, foliage fades, yellows browns or wilts |
Root rots: discolored and softened roots.
|
Remove diseased plants from their pots, cut out portions (rotten), and replant remaining healthy sections. Take cuttings and root them in sterile potting mix. |
Leaf yellowing, foliage fades, yellows browns or wilts |
Leach soil at least three times with pot volume of fresh water. |
|
Bleached or whitened leaves | Excessive light or sunburn. | Acclimate plants slowly to higher light intensities, especially when moving them outdoors in the summer. |
Fine stippling (numerous tiny dots caused by spider mite feeding) |
Spider mites: minute pests that feed on lower leaf surfaces, webbing may be visible. | Regularly rinse plants with water to keep down spider mite problems. Use a registered houseplant spray to control mites. Plants damaged by heavy mite feeding can be injured by insecticidal sprays. Severely damaged plants should be discarded. |
Leaf spots and leaf blotches | Water spots, sunburn, various fungi, bacteria. | Do not splash water onto plants with fuzzy leaves such as African violets. Remove spotted leaves and improve air circulation to reduce leaf diseases. |
Leaf or shoot blackening | Cold Injury: symptoms may continue for up to a week after exposure. | Protect plants from temperatures below 50° F. |
Leaf scorch | Abiotic stresses (not related to disease or insects) such as over-fertilization, high soluble salts, lack of water: scorching symptoms can occur along leaf margins or between veins. | Leach excessive fertilizer from potting mix by flushing with water or repot with fresh potting media. |
Stunted, twisted and distorted plant growth | Aphids: small soft-bodied sucking insects. Cyclamen mites: predominately a pest of flowering plants. New growth is affected first. Viruses: foliage appears mottled green and yellow. Plants may be stunted. | Aphids can be controlled with a stream of water or with a registered insecticide. Plants infested with cyclamen mites or infected with viruses should be discarded. |
Leaf mottling | Viruses: foliage appears mottled green and yellow. Plants may be stunted. | No effective treatment, discard infected plants. |
White powdery coating on leaves | Powdery mildew fungi: grows on the leaf surface. | Provide better air circulation and pick off infected leaves. Spray with a registered fungicide if disease is severe. Check horticultural oil labels for powdery mildew control listings. |
Fuzzy gray growth on leaves or flowers | Gray mold: frequently infects old faded flowers or older, lower foliage. | Provide better air circulation. Pick off infected flowers or leaves. Remove old blooms or foliage. |
Fluffy white wax | Mealybugs: white cottony insects may occur on foliage, in leaf axles, leaf sheaths, roots, and bud scales. | Use a registered houseplant spray to control mealybugs or use a cotton swab dipped in alcohol to kill individual mealybugs. |
Leaves eaten or chewed | Check plants that have been outside for the summer for pests such as caterpillars, leaf-feeding beetles, weevils, grasshoppers, crickets, slugs, and earwigs. | Handpick pests and repot plants before moving plants inside. |
Few or no flowers | Low light levels, excessive fertilizer, cyclamen mites. | Increase light levels by relocating plants closer to a light source or add additional artificial light sources. Cyclamen mite infested plants should be discarded. |
Spindly growth | Low light levels or excessive fertilizer, (high soluble salts). | Increase light levels by relocating plants closer to a light source or add additional artificial light sources. Reduce fertilizer applications during winter. Irrigate from the top of the pot to leach out excess fertilizer salts. |
Poor growth | Poor growing conditions, insects and diseases. | Follow recommended practices. |
Flying insects | Whiteflies: tiny white insects flying around plants. Fungus gnats: tiny black flies flying near plants or near light sources. |
Use a registered insecticide for whiteflies. Allow potting media to dry between waterings. |
Insects in potting media | Ants, sowbugs, springtails earwigs, millipedes, slugs, slugs: often brought in from outside when relocating plants from outdoors. | Repot plants with fresh potting media. Beneficial nematodes may be used to control fungus gnat larvae. |
Based on HGIC publication HG 60 IPM Series: Houseplants, authors Dave Clement, Ph.D., Extension Specialist, Plant Pathology and Mary Kay Malinoski, Extension Specialist, Entomology (Retired).