Oats

Manageable at garden scale - protect the seed at sowing and the grain at ripening; the open oat panicle is a little more exposed to birds than a tight spike. Cutting early at soft dough and finishing the drying under cover works well.

Fruit disappearing from the outermost, most exposed parts of the plant first, and from the top of a tree where you cannot reach anyway. Single neat pecks and gouges in ripening fruit, with several fruits sampled rather than one eaten through - the classic sign that it was birds rather than an animal. Heads of grain or seed going visibly lighter and emptier as they ripen, with hulls and chaff scattered underneath. Freshly sown seed vanishing off the surface of a bed before it germinates. Bird traffic in and out of the plant picking up as the crop colors, and birds waiting on nearby wires and branches. Wasps arriving at the pecked and split fruit shortly afterward.

There is no treatment once a crop is being taken - only protection and timing, so the answer is to get netting on and to pick what is ready. Reflective tape, flash ribbon, spinners, and decoy predators do work, but only for a few days at a time: birds habituate fast, so move and rotate them and never rely on them as the main defense for a crop you care about. Cut and gather grain or seed heads a little early, at firm dough, and finish drying them under cover instead of leaving them standing for the flocks. Plant a little extra, or a decoy crop the birds prefer, and accept sharing anything that crops heavily. On a wild or foraged patch, fruit going to birds and small mammals is the point of the plant rather than a problem to solve.

Net, and net early. Bird netting draped over a frame or hoops so it stands off the fruit, with the edges closed at ground level, is the only thing that reliably works at harvest scale - and it has to go on before the crop starts to color, because once birds have found the food they are far harder to displace. Keep fruit trees small enough that netting them is actually feasible; that decision gets made years earlier, at planting. Bags of mesh, organza, or paper slipped over individual heads, clusters, or prize fruit protect a small crop without netting the whole plant. Then shorten the exposure: pick promptly and completely rather than leaving ripe fruit hanging as a lure, clear split and dropped fruit that draws birds and wasps alike, and where a crop can finish off the plant, harvest a little early and ripen or dry it under cover. Rake in or cover broadcast seed so it is not lying in plain view.

Birds find ripening fruit and seed before you do. Robins, waxwings, starlings, catbirds, jays, sparrows, finches, blackbirds, and doves all work a garden, and the pressure arrives in a narrow window - the last days before harvest, when sugar rises, color changes, and the crop softens or the grain hardens. A flock can strip a small planting in a day or two, and birds that only peck rather than take whole fruit still leave wounds that rot or draw wasps. Squirrels, chipmunks, and other wildlife usually turn up on the same crop at the same time. This is competition rather than disease: the birds are not harming the plant, and a big tree or a heavy-cropping bush often has enough for everyone - but on a small planting it can be the difference between a harvest and none.

The mycotoxin makes scab a safety issue, not just a yield one - discard suspect grain, and dry small-plot sheaves somewhere genuinely airy.

Prematurely bleached, straw-colored spikelets or whole heads while the rest is green, often with pink-orange fungal growth at the base of the florets, and shriveled, chalky-white 'tombstone' kernels.

No home cure - discard shriveled, discolored, musty, or moldy grain rather than eating or feeding it; the toxins survive cooking. Prevention through rotation and fast, thorough drying is the control.

Rotate away from corn and small-grain residue, avoid dense stands that stay wet, and harvest and dry promptly - sheaves left damp in wet weather are the home-scale version of the problem.

A fungal disease infecting the heads in warm, wet weather at flowering, shriveling the grain and contaminating it with mycotoxins - a food-safety concern as well as a yield loss. Oats are among the cereals most affected by the T-2 and HT-2 toxins.

More a management issue than a pest - the fix is lean feeding and sturdy varieties rather than any treatment.

Whole patches bent or flattened to the ground, especially after storms or on rich, over-fertilized ground, with tangled stems and heads in the dirt.

Little can be done once lodged - harvest lodged teff carefully; prevention through lean feeding and good variety choice is the real answer.

Feed lightly (avoid excess nitrogen), grow teff on lean-to-moderate soil, avoid over-watering, and choose sturdier or shorter varieties where available.

The flattening of a stand when tall, weak stems bend or break under their own weight, wind, or rain - teff's most significant weakness, made worse by rich soil, excess nitrogen, and heavy heads, and it tangles the crop and complicates harvest.