A disadvantage of vegetative propagation is that diseases are easily transferred to offspring. This is because in vegetative propagation, new plants are grown from a piece of the parent plant, such as a cutting or a runner. If the parent plant is infected with a disease, the disease can be easily passed on to the offspring, as they are genetically identical to the parent plant. This can lead to the spread of the disease throughout a population of plants, and can make it difficult to control the disease. On the other hand, the advantage of vegetative propagation is that the plants are true to type, meaning they have the same genetic characteristics as the parent plant.