Why Does My Primrose Look Unhealthy?

Do the leaves have notched edges?

Do the leaves have large, ragged holes in them?

Is there a white, waxy material on the soil around the base of the plant; plant lacks vigor?

Are the flowers covered with gray mold, leaves may be blotched or discolored?

Are the seedlings dying?

Are the leaves greenish-yellow and the growth rate is poor?

Are the stems, crowns, and/or roots rotted, leaves are wilting?

Notched edges on the leaves are caused by Vine weevils. The wingless, black bugs are adults that feed on the leaves of several plants. You can get rid of them by handpicking or by gently shaking the plant and collecting fallen beetles. Spray leaves several times with pyrethrin for major infestations.

Large, ragged holes in the leaves are caused by slugs and snails. Slugs and snails feed on the plant leaves usually at night. To control slugs and snails use diatomaceous earth around your plants. You can also handpick them during the night or use shallow dishes filled with beer as a trap.

Root aphids are from the family Phylloxera, a near-cousin of aphids. They’re about the same size or slightly smaller than stem-and-leaf aphids with shorter legs and antennae. Introduce beneficial nematodes into the soil at the first sign of root aphid infestation. Introduce ladybugs in your garden. Use pyrethrum-based spray if the infestation is severe.

Gray mold on flowers is probably caused by fungal disease - Botrytis blight. You can prevent Botrytis blight disease by planting flowers in areas with good air circulation. Water plants sparsely. Severely infected plants should be removed. Spray weekly with a copper fungicide until the disease is under control.

If the seedlings are dying the probable cause is a damping-off disease. Damping-off is caused by various soil fungi. Damaged seedlings can't be healed so, the best course of action is to remove them. To prevent damping-off let the soil surface dry between waterings, thin seedlings to avoid overcrowding and do not add nitrogen fertilizers until plants have developed leaves.

Greenish yellow, strap-shaped leaves followed by a poor growth is caused by Aster yellows disease. There is no cure for Aster yellows, so the infected plants should be destroyed. Prevent the disease by controlling leafhoppers. Spray the plants with the insecticidal soap 3 times, once every 3 days.

Primroses are susceptible to several Crown or Root rot diseases. Crown injury and excess moisture increase the chances of infection. Choose well-drained sites. Add organic matter to improve soil drainage. Remove and discard infected plants and the surrounding soil.

If the roots are damaged the culprits are rodents like mice and voles. The presence of a pet dog or cat often deters rodents. Line planting beds with screen or hardware cloth to keep pests from burrowing around plants.