Why Have the Leaves on My Clematis Turned Brown?

Sunlight

• Excessive exposure to direct sunlight causes the leaves of the clematis vine to turn brown and appear scorched or burnt. The condition is exacerbated during prolonged periods of drought or in dry weather, when soil moisture is insufficient. If possible, transplant the vine to a spot in your yard that offers protection from the direct rays of the afternoon sun, especially during the summer, or install a shade cloth over the plant. Provide the vining plant at least 1 inch of water every week to keep the soil moist and keep the roots from dehydrating.

Clematis Wilt

• Clematis wilt is a serious disease that damages the entire plant. The infected clematis vine suddenly collapses before its foliage turns brown or black and dies. The disease is difficult to diagnose because it appears suddenly, sometimes even overnight, without prior warning. Prune infected stems of the plant just below the black and damaged parts. If necessary, prune as close to the ground or even just under the soil line to remove the damaged section. Because the wilt does not damage roots, most clematis vines grow back the next season.

Pests

• Pests cause the foliage of clematis vines to turn brown and appear shriveled. Spider mites are tiny pests that sap essential juice from the foliage of the plant, causing the leaves to turn a lighter shade of brown, then a deeper tan, before falling off. The damaging pests also form delicate white webs on the undersides of leaves. Direct a spray of water from a hose to dislodge spider mites and larvae, or spray infestations with insecticidal soapy solution.

Root Rot

• Caused by phytophthora fungi, root rot is a fungal disease that causes the roots and crown of clematis vines to rot and turn black. Infected roots fail to absorb and transport water and nutrients to different parts of the plant, thus causing the foliage to turn brown and drop prematurely. Left untreated, the disease progresses to stunt plant growth and cause cankers on the trunk. In some cases, infected bark secretes black or red sap. Whenever possible, select resistant varieties to reduce chances of the disease. Plant clematis vines in well-draining soil. Prune infected parts of the plant, or treat with a registered fungicide.