Pear

Young trees are far more vulnerable than mature ones - the first few years are the risk window, for antler rubbing as much as for browsing.

Growth cleanly missing overnight, with the plant browsed back to a level line about as high as a deer can comfortably reach. Ragged, torn stem ends rather than the clean angled cut a rabbit leaves - the single most reliable identifier. Buds and flowers gone while the foliage below is untouched, since deer often take the best part first. Hoof prints and droppings in soft ground near the damage. Repeat visits, with fresh damage each morning once a planting has been found. On young trees, shredded and stripped bark and broken low branches in autumn - that is antler rubbing rather than feeding.

There is no chemical fix, only exclusion and recovery. Get physical protection up immediately after the first damage, because deer return to a known meal, and reinforce or rotate whatever you were relying on before. Most plants regrow from browsing if the crown and roots are intact - feed and water a grazed plant and protect the regrowth while it comes back. What does not recover in the same season is anything whose buds or flowers have been taken, and a young tree whose bark has been rubbed right around the trunk is usually lost. Where deer pressure is genuinely heavy, the honest answer is to fence properly or to grow the plants deer leave alone, rather than to keep replacing losses.

Fencing is the only thing that reliably works. Eight feet is the standard for excluding deer, or two parallel four-foot fences a few feet apart, which they will not jump because they cannot judge the landing. Short of that, cage individual plants: a sturdy wire cage or trunk guard around every young tree, left on until the trunk is thick and the canopy is above browse height, prevents both browsing and antler rubbing and is the single highest-value thing you can do for a young tree. Repellent sprays do help at moderate pressure, but they wash off and deer habituate, so reapply after rain and rotate between different types through the season. Motion-activated sprinklers, scent deterrents, and noise devices work for a while and then stop. Siting matters too: plants close to the house, in daily traffic, and screened behind other planting get browsed less than the same plant out at the boundary.

Deer are the largest garden problem across much of the country, and where pressure is high they set the limit on what you can grow at all. They browse at night and around dawn and dusk, taking tender shoots, leaves, buds, flowers, and fruit within about five feet of the ground, and they come back night after night to anything they have found and liked. Because they have no upper incisors they tear rather than cut, leaving ragged stem ends - that is how you tell deer damage from a rabbit's clean angled cut. In fall, bucks rub their antlers on young trunks and can strip the bark right around a stem, which kills a young tree outright. Palatability varies enormously between plants and between seasons: a herd short of food in late winter eats things it ignores in June, and no plant is truly deer-proof.

A pear-only pest - it does not attack apples. Worst on stressed trees and where broad-spectrum sprays have wiped out its natural enemies.

Sticky, shiny honeydew on leaves and fruit, black sooty mold, tiny cicada-like nymphs and adults on new growth, and yellowing, dropping leaves on a stressed tree.

Dormant and early-season horticultural oil; kaolin clay as a repellent; targeted insecticides only when populations are high, choosing products that spare beneficials. Use only a product labeled for this crop, follow the label exactly, and observe the pre-harvest interval before you pick. Reducing tree stress is half the battle.

Keep trees moderately vigorous (over-fertilized succulent growth feeds them), apply dormant horticultural oil to smother overwintering adults and eggs, and protect the predators (ladybugs, lacewings, anthocorid bugs) that normally keep psylla in check.

A tiny sap-sucking insect specific to pears - the most damaging pear-only pest. Nymphs coat leaves and fruit in sticky honeydew that grows black sooty mold, weakening the tree, russeting the fruit, and, in heavy infestations, transmitting a decline disease.

An eastern and midwestern pest, largely absent in the arid West. Less damaging on pears than on stone fruit, but still worth watching at petal fall.

Crescent- or half-moon-shaped scars on newly set fruit within a few weeks of petal fall, a heavy premature fruit drop, and small grubs inside the dropped fruit when you cut one open.

Spread a sheet under the tree at dawn and jar the branches: the beetles play dead and drop, and you can collect them. Where damage is heavy, a targeted insecticide at petal fall and again shortly after is timed to adult activity - use only a product labeled for the crop you are treating, follow the label exactly, and observe the pre-harvest interval before you pick.

Pick up and destroy dropped fruit promptly and consistently - the larvae finish developing in the drops, so leaving them under the tree simply raises next year's population. Kaolin clay applied to the young fruit deters egg-laying without an insecticide.

A small snout beetle of the eastern and midwestern US that cuts distinctive crescent- or half-moon-shaped scars into newly set fruit to lay its eggs. The larvae tunnel inside, so the fruit comes out misshapen and wormy or drops early, and the larvae then finish their development in the fallen fruit. It attacks stone fruit and pome fruit alike, and it is largely absent from the arid West.