Rose-replant disease explained

Steve and Val Bradley reveal why new roses often fail when planted in the same place as old ones and offer two solutions to help overcome the problem

- Steve and Val Bradley

ANCIENT wisdom tells us that there are certain circumstances when you can’t replace one type of plant with the same type in the same spot because the new plant will struggle and may die. This is referred to by a number of names, such as rose-replant disease, rose sickness, soil sickness or, in the case of apples, SARD (specific apple replant disease). The saying ‘Never replace pip with pip or stone with stone’ is often quoted by gardeners and growers when it comes to trying to replant apples, cherries, peaches, pears, plums, quinces and roses where the same type of plant was growing before.

Barely understood disease

Replant disease has long been recognised, but was, until recently, a barely understood problem. It is a specific condition that occurs when a certain plant is replaced with the same type. For most plants, doing this does not cause a problem. Herbaceous perennials, for example, are regularly dug up, divided and young divisions replanted in their original position. However, particularly with roses and other related members of the rose family, the newly introduced plant starts to struggle more or less from day one.

It has now been established that one of the main reasons for this problem in roses is the presence of soil organisms that develop around the roots of the older plant. These, including beneficial fungi, remain on any root fragments left in the soil after the previous plant has been removed.

Mycorrhizal fungi