What Is Wrong With My California Pepper?

Are the leaves small, discolored, and drop early, clusters of honey-colored mushrooms may sprout at the base of the plant?

Are the leaves covered in coarse stippling and may appear silvery?

Do the leaves have holes?

Are the leaves covered with small bumps?

Are the older leaves turning yellow and wilting, an overall decline in plant vigor is apparent?

Armillaria root rot is a fungal disease that cannot be effectively controlled once it has become established in an orchard. Diseased or dead plants should be uprooted and removed. Planting resistant rootstocks is the most effective method of preventing the disease.

These symptoms indicate thrips. Thrips are tiny, yellow to black flying insects. They hide under the leaves. Severely infected plant parts should be removed and destroyed. Control thrips by introducing lady beetles or lacewings, their natural predators. Insecticidal soap helps in severe infestations.

Several species of leaf-feeding caterpillars will feed on the California pepper tree's 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.

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.

These symptoms indicate fungal disease Verticillium wilt. Verticillium infects a wide range of plant species. Affected branches can be pruned out. Severely diseased trees may need to be removed. The best way to avoid or combat the disease is to keep plants otherwise healthy, for infected trees are capable of recovering with proper cultural care. No fungicides are available to cure infected trees.

Peppertree psyllid (Calophya rubra) feed on host foliage by sucking fluids from the plant tissue. On California pepper, leaves develop a pit around the spot where each psyllid settles and feeds. However, the foliar distortion caused by Peppertree psyllid feeding can be easily overlooked on the finely divided leaves of California pepper. A parasitic wasp (Tamarixia schina) usually provides sufficient control of Peppertree psyllid, and no additional control is needed. Improving the host’s health will increase its ability to tolerate psyllid activity. Provide adequate soil drainage and remove landscape plants or turf growing near trunks.