What Is Wrong With My Toyon?

Are there wet, sappy areas on the bark of the main trunk, which may crack?

Do the leaves have holes?

Did the flowers and leaves suddenly blackened, and the tips of growing shoots bend over?

Do the leaves have spots or blotches?

Are there any reddish-brown streaks on the outer and inner bark, as well as gum or dark sap oozing from the diseased area?

Are the leaves covered with small bumps?

Are the leaves yellow and the plant looks weakened?

Larvae of flathead borers tunnel beneath the bark, causing wet, sappy on the bark of the main trunk. Boring may kill limbs or entire trees. Prevention is the most effective management approach for flathead borers, which typically attack trees that have been previously injured or damaged. Providing proper care and protecting landscape plants from injury will make them less attractive to the borers. Avoid pruning spring-summer while adults are active. Properly dispose of infested wood material, as beetles may emerge from logs and attack nearby plants.

Several species of leaf-feeding caterpillars will feed on toyon leaves. They may also feed on stems, flowers, and fruit. Handpick and destroy caterpillars, or spray plants with BTK if caterpillars are feeding. Many foliage-feeding caterpillar populations are controlled by general predators, parasites, or naturally occurring viruses.

These symptoms indicate a bacterial disease - Fire blight. Control fire blight during the growing season by pruning off branches a foot below infected sections. Between each cut, dip pruning shears into isopropyl alcohol or a 10 percent bleach solution to prevent spreading the disease as you prune.

Your plants are suffering from fungal leaf spot. These can come from several fungi. Spots may enlarge rapidly, especially in wet weather. Destroy infected leaves or plants. Spray plants with sulfur to prevent the disease from spreading, especially if the weather is wet. Spray between rains. Prevent problems by thinning plants to provide good air circulation. Fallen leaves and debris should be removed promptly to avoid spreading the disease.

These symptoms indicate fungal disease Phytophthora Root and Crown Rot. Phytophthora pathogens are favored by wet conditions, and the risk of disease can be reduced with good water management. The disease tends to affect plants in poorly drained areas, where susceptible plants are surrounded by standing water or saturated soil for prolonged periods. Provide adequate drainage and know the water needs of individual plants.

Leaves covered by small bumps are caused by scales. These tiny, shelled insects often feed on the undersides of the leaves, causing an unhealthy appearance with yellowish blotches on the upper leaf surfaces. Scrape off minor infestations with your fingernail. Prune out badly infested growth, or use a soft brush and soapy water to gently scrub the scales off the stems. Control scales by spraying insecticidal oil during the growing season.

Yellow leaves and stunted look are caused by whiteflies. These tiny, mothlike flies and their larvae feed by sucking plant juices. Whiteflies secrete honeydew, a sugary substance that makes leaves sticky to the touch. Control whiteflies by eliminating garden weeds and by introducing green lacewings in the garden. Spray infested plants with insecticidal soap every 3 days for 2 weeks.

Feeding of the thrips causes stippling, discolored flecking, or silvering of plant surfaces, accompanied by black flecks of frass. Thrips are tiny, yellow to black flying insects. They hide under leaves and inside flowers. Severely infested plant parts should be pruned off and destroyed. Control thrips by introducing lady beetles or lacewings. Insecticidal soap helps in severe infestations.