Why Do My Raspberry Leaves Have Yellow Mottling and Stunted Growth?

Raspberry plants showing yellowed, mottled or distorted leaves alongside declining yields and progressively weaker canes are almost certainly infected with one or more raspberry viruses. Viral disease is widespread in older raspberry plantings and spreads continuously through aphids, pollen and contaminated planting material. Once a plant is infected there is no cure, but knowing what is happening helps you decide when to remove old material and how to replant cleanly.

The main raspberry viruses

Raspberry mosaic virus complex — a combination of several viruses spread by the raspberry aphid — causes yellow-green mottling and puckering of leaves, reduced cane vigour and smaller fruit. Raspberry bushy dwarf virus (RBDV) spreads by pollen and causes stunted bushy growth and crumbly berries. Raspberry leaf curl virus causes downward rolling of leaves and yellow marginal patches. Infected plants decline over years rather than dying suddenly — yield and fruit quality gradually decrease.

How long can infected plants continue?

A row that began showing mild symptoms two or three years ago will typically be producing noticeably less by now, and will continue to decline. Virus-infected raspberry plants can remain in the ground indefinitely and still produce some fruit, but they also serve as a reservoir that continues to spread infection to any healthy canes nearby. The practical threshold for removal is when yield is significantly impacted or when you plan to replant — at that point, remove all old material before introducing new canes.

Replanting after virus

Do not replant raspberries in the same row for at least two years — aphids and soil-carried inoculum reduce but do not disappear immediately. Use only certified virus-free canes from a reputable supplier; avoid using suckers or canes from a friend's garden if the health status of that stock is unknown. Choose varieties carrying resistance to the raspberry aphid, which directly reduces virus transmission risk.