Chokecherry

The signature disease of plums and cherries in the eastern US and Canada: a fungus (Apiosporina morbosa) that forms hard, black, crusty, warty swellings that encircle and girdle twigs and limbs, deforming and eventually killing branches. Left unchecked it takes over a tree over a few years.

Watch for: Olive-green, corky swellings on new growth that harden and turn coal-black and warty, encircling twigs and branches; worst on wood 1-2 years old.

Prevent: Cut out every knot 4-6 inches below the swelling during dormant winter pruning, sterilizing the saw between cuts and burning or bagging the wood; plant more-resistant varieties; and remove wild cherry and plum nearby, which harbor the disease.

Treat: Prune out and destroy all knots annually - this sanitation is the core control. Fungicide sprays from bud break through early shoot growth help in high-pressure orchards but don't replace cutting out the knots.

Chokecherry is THE wild reservoir this disease is usually spreading from - the wild cherry that orchard guidance tells you to remove. If you grow one deliberately, you take on the job of cutting every knot out each winter, or you become the source for every cherry and plum around you. Purple-leaf Schubert and Canada Red are especially badly hit.

Chokecherry leaves, twigs, bark and pits contain cyanogenic glycosides, which release hydrogen cyanide when plant tissue is damaged. The critical fact is that WILTING dramatically raises the risk: leaves on branches broken by wind, cut in pruning, browsed and left hanging, or frost-damaged are far more dangerous than leaves on an intact growing plant. Ruminants are the most vulnerable because rumen conditions release the cyanide efficiently, and cattle, sheep and goats have died from a single feed of wilted chokecherry brush; horses are also at risk. Onset is fast - often within 15 to 60 minutes - and animals are frequently found dead with no observed illness. Chokecherry is consistently among the top causes of plant-related livestock death in the western United States. For people the hazard is far smaller but not zero: it is the reason the pits must be strained out of cooked fruit rather than ground into it.

Watch for: Wind-broken or storm-thrown branches lying inside a pasture, paddock or corral. Piles of fresh prunings or brush tossed over a fence line - this is the classic scenario. Chokecherry growing along a fence where animals can reach through and browse it. Foliage that has been frosted or is drought-wilted while still within reach. In an affected animal: sudden distress, rapid labored breathing, staggering, collapse, and bright cherry-red mucous membranes and blood, progressing to death within an hour. Because onset is so fast, dead animals near a chokecherry thicket with no other explanation should be treated as a suspected cyanide case.

Prevent: Site the plant so this cannot happen: never plant chokecherry overhanging or adjacent to grazed ground, and fence stock well back from existing thickets rather than relying on the animals to avoid it. Gather every pruning and every wind-broken limb and dispose of them where no grazing animal can reach - burning or hauling out, never dumping over a fence. Walk fence lines after every windstorm through the growing season. Do not turn hungry animals into an area with chokecherry in it, since hunger is what makes them eat something they would normally leave. In the kitchen, cook fruit whole and strain the pits out; never grind, blend, pound or crush chokecherry pits into juice or preserves.

Treat: There is no home treatment for a poisoned animal - cyanide poisoning moves too fast, and survival depends on a veterinarian administering specific antidotes within minutes. Call a veterinarian immediately, move the remaining animals off the area, and remove the source. The realistic response is entirely preventive: control where the plant grows relative to stock, and control where the cuttings go. For people, if pits have been crushed into a batch of juice or preserves, discard the batch rather than trying to judge how much is too much, and contact Poison Control if anyone has consumed a quantity of crushed pits.

This is the single most important thing to know about chokecherry, and it is a siting decision, not a maintenance one. If you keep or border livestock, put the plant somewhere else. The safe home kitchen rule is simple: whole fruit into the pot, pits strained out and thrown away.

A phytoplasma disease of stone fruit spread by leafhoppers, causing small, pale, bitter, unmarketable fruit, leaf reddening or yellowing, and progressive decline and death of cherry, peach and nectarine trees. There is no cure and no treatment for an infected tree. The disease persists in wild reservoir hosts - chokecherry above all - which show relatively mild symptoms themselves while feeding leafhoppers that carry it into orchards. It has caused severe, ongoing losses in cherry-growing regions of the Pacific Northwest and the Great Lakes.

Watch for: On chokecherry, reddening or bronzing of leaves in mid to late summer, sometimes with witches-broom shoot proliferation and stunting - symptoms mild enough to be easy to miss. On nearby stone fruit, small pale bitter fruit that never ripens properly, one branch declining ahead of the rest, and trees going backwards year on year with no obvious pest.

Prevent: Reservoir control is the whole strategy. Do not plant chokecherry within several hundred feet of cherries, peaches, or nectarines, and if you already have both, removing the chokecherry is the standard recommendation in affected regions. Buy certified clean nursery stock for stone fruit, and manage leafhopper habitat in and around the orchard.

Treat: None. Infected stone-fruit trees do not recover and are removed to protect the rest of the planting. Because the reservoir is what keeps the cycle going, the meaningful action is removing infected chokecherry near susceptible orchards rather than treating anything.

This is the second half of the reason chokecherry belongs away from stone fruit. The plant itself is barely troubled - it is what it hands on that matters. If commercial cherry or peach orchards operate near you, check local extension guidance before planting one at all.

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.

Watch for: 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.

Prevent: 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.

Treat: 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.

Chokecherry is a preferred browse plant across the West, and deer are not harmed by the foliage the way livestock are - wild ruminants browse it routinely without ill effect at the amounts they take. Cage young plants for the first few years; an established thicket outgrows browse pressure and simply gets denser.

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.

Watch for: 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.

Prevent: 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.

Treat: 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.

A big thicket usually carries enough for everyone, and feeding waxwings, grosbeaks, and grouse is half the point of planting one. If you want a reliable jelly crop, net one or two accessible stems as the fruit darkens - netting a whole thicket is not realistic. Yellow-fruited selections like Boughen's Golden are largely ignored by birds because the fruit never looks ripe.

Tent caterpillars build conspicuous silk tents in the branch forks of cherry, chokecherry, apple, plum and related trees in spring, and feed outward from them on the new leaves. Eggs are laid in a hard, shiny, dark band encircling a twig in summer and hatch just as the buds open the following spring, so the caterpillars arrive exactly when the foliage is softest. Colonies grow fast and a heavy year can strip a small tree completely by early summer. The damage looks alarming and is genuinely ugly, but a healthy established tree refoliates within a few weeks and suffers no lasting harm; repeated defoliation over several consecutive years is what weakens a plant. Populations run in multi-year cycles, so a bad spring is often followed by another and then by several quiet ones.

Watch for: Dense white silk tents in the crotches of branches from the moment the leaves open, growing larger week by week as the colony expands. Bare, stripped twigs radiating out from each tent while the rest of the tree still has leaves. Hairy caterpillars massed on the tent surface in the morning and evening and out feeding in between. Hard, shiny, dark egg bands wrapped around pencil-thick twigs, visible on bare wood all winter - the easiest time to find and remove them. Frass and shed skins accumulating below the tents.

Prevent: Look for the egg bands on bare twigs through the winter and prune or scrape them off - one band removed in February is a whole colony that never appears. Then check branch forks weekly from the moment the buds break, because a tent found small is trivially dealt with. Leave the birds, parasitic wasps, and predatory beetles alone; they take a heavy toll on tent caterpillars and are the reason outbreaks collapse on their own. Do not attempt to burn tents out of a tree - it does more damage to the tree than the caterpillars ever would.

Treat: Pull the tents out by hand in the early morning or evening while the caterpillars are inside, wearing gloves, and drop the whole mass into soapy water. On a small tree this alone is a complete solution. For a heavy infestation on a young plant, Bt (Bacillus thuringiensis) applied to the foliage the caterpillars are feeding on works well and spares beneficial insects, but it only affects small caterpillars, so timing is early. On an established tree, doing nothing is a legitimate choice: it refoliates and moves on. Anything you spray must be labeled for the plant you are treating.

Chokecherry is one of the preferred hosts - if there are tent caterpillars in your area, they will find it. Damage is almost always cosmetic on an established thicket, and the eastern tent caterpillar is a native insect that feeds a great many birds.