Act now with diseased fruit trees
IT’S sad when a fruit tree dies, especially if it’s been struck down by a root-killing disease such as honey fungus or phytophthora. Quite often, the tree has been happily growing for decades; it’s only as its vigour declines with age that aggressive pathogens gain the upper hand and invade the root system.
With such ‘soil-borne’ diseases, it’s not simply a case of digging out the old tree and replacing it with a new one. Remnants of the diseased material will remain in the soil, so replanting with a related tree runs the risk of the new planting becoming infected, too.
Excavate the plant and check the roots. A strong mushroom smell and white fungal sheet under the root ‘bark’ indicates honey fungus; this often attacks apples, pears and stone fruits. Roots stained grey/black inside with a cidery smell indicates phytophthora (encouraged by waterlogging).
Remove as much of the root system as possible. Dig out a soil pit at least
4ft (1.2m) wide and
2ft (60cm) deep, bagging up the earth and dispose of it at a local household waste depot, taking care not to trample the soil around your garden. Refill the hole with new topsoil, either from other parts of the garden or bought in.
When planting a new tree, add a root inoculation of mycorrhizal fungi (Rootgrow). This strengthens the root system, so it is less vulnerable to attack.