How long an orchard lives

Three things govern how long a fruit tree lives: the rootstock, the disease pressure, and whether anyone decides to remove it. Rootstock is the largest single factor. A dwarfing stock produces a tree that comes into bearing quickly, exhausts itself comparatively quickly and has little reserve to recover from damage. A seedling or vigorous stock produces a tree that takes years to crop and then goes on for decades.

Disease pressure sets the ceiling in practice. In the wet English west, canker is what eventually kills most old apple trees, working in through leaf scars and pruning wounds and killing limb after limb until the tree is a shell. Wind, honey fungus, waterlogging and the sheer mechanical failure of an over-extended crown do the rest.

The third factor is a decision, not a biological limit, and it is the one that actually determines most orchard lifespans. Bush orchards are removed while still healthy because their yield has fallen below what a replacement would give. Standard orchards are removed because the land is wanted for something else.

Perry pears grown on pear seedling rootstock make very large, very long-lived trees. A mature specimen can exceed fifteen metres, carry an enormous crop, and stand for two hundred years or more; several named trees in Gloucestershire and Worcestershire are documented across multiple generations of record. The proverbial formulation in the Three Counties — that a man plants pears for his heirs — is a straightforward description of the return period rather than a piece of decoration.

The delay is real and severe. A perry pear may take fifteen years to give a worthwhile crop and forty to reach its stride, at which point the person who planted it is unlikely to be picking it. That single fact explains most of what is peculiar about perry: why the pears cluster in a small area of the Severn and Wye catchments where they were planted long ago, why so few new perry orchards were ever planted, and why the loss of an old tree cannot be made good within a working lifetime.

It also explains why perry pear conservation is done tree by tree. When the surviving stock of a cultivar is a handful of ancient trees in known hedgerows and orchards, grafting wood from them onto new rootstocks is not a heritage gesture but the only mechanism by which the variety continues to exist.

Time is what converts a planting into a habitat. Bark fissures deepen and hold lichen and invertebrates; limbs die and stay attached; heartwood decays and hollows the trunk while the living sapwood carries on; rot holes fill with wood mould that specialist beetles need and that exists almost nowhere else in the lowland landscape. None of this happens in thirty years. Most of it needs sixty or more.

The same processes reduce the crop. A veteran tree carries less fruit, carries it more irregularly, and drops limbs. This is the trade-off at its starkest: the features that make an old orchard ecologically irreplaceable are the same features that make it agriculturally marginal, and pretending otherwise helps nobody. An honest account says that keeping veteran orchard trees standing is a decision to accept lower fruit output for a different kind of return.