Hardy Kiwi

A soil-borne water mold (Phytophthora species) that rots feeder roots and, on many plants, the crown at the soil line whenever the ground stays saturated. Rotted roots cannot take up water, so the plant looks drought-stressed even in wet soil: the canopy thins, leaves go small and pale, growth stalls, and dieback works in from the tips over months or years. It is the commonest cause of death in plants that want moisture but cannot tolerate standing water, and it travels in surface water and on tools, boots and moved soil.

Watch for: Wilting, yellowing and stunting that does not improve with watering, a thinning canopy of small pale leaves, and dieback from the shoot tips. Dig and the feeder roots are dark, soft or brittle rather than white and firm, and on many plants the tissue at the base of the stem is discolored under the bark. Worst in low spots, and wherever a downspout, driveway or compacted path drains into the bed.

Prevent: Drainage is the whole defense. Plant on a mound, berm or raised bed in heavy soil, and never in a hollow that holds winter water. Redirect roof and hard-surface runoff away from the planting, water deeply but infrequently so the surface dries between waterings, do not pile mulch against stems, and do not overwater in cold weather when the plant is using little. Use resistant rootstocks or tolerant varieties where they exist for the crop, and never move soil from an infected area.

Treat: Very hard to reverse once established. Improve the drainage immediately, cut watering back, and mulch with coarse material rather than fine, which stays sodden. Remove severely affected plants and correct the site before replanting - and do not put another susceptible plant back into the same wet spot. Phosphonate (phosphite) treatments can suppress it in a valuable specimen, but drainage and siting do far more.

The one disease that genuinely kills hardy kiwi. The vine is thirsty but wholly intolerant of waterlogging, so wet ground is its real vulnerability - plant on a raised mound or berm and treat drainage as part of the planting job, not an afterthought.

Actinidia vines break dormancy early, often on the first run of mild days in late winter or early spring, and the shoots they push are among the most frost-tender growth in the fruit garden. Dormant wood is extremely tough, but once buds swell and the first leaves unfold, temperatures around 30F kill them outright, and a hard late freeze takes the season's growth along with the flower buds it was carrying. The vine itself usually survives and pushes a second flush from secondary buds, but that flush carries little or no fruit - so a completely winter-hardy vine can go several years without a crop in a site that keeps getting caught. Damage is worst in low ground where cold air pools, against warm south-facing walls that coax the vine into growth too early, and in seasons following an unusually mild late winter.

Watch for: New shoots and unfolded leaves that blacken, go limp and hang wilted within a day or two of a clear cold night, then dry to brown. Growth scorched at the tips while wood further back stays green under a scratch. Flower buds that shrivel and drop without ever opening. Damage that stops at a distinct height, with everything below the level of pooled cold air hit and the growth above it untouched. A second, later flush of shoots pushing from further back on the arms - that is the vine recovering, and it is worth noting whether it carries flowers, because usually it does not. Consistently worse damage in a hollow, at the bottom of a slope, or behind a solid fence or hedge that dams cold air.

Prevent: Siting is most of the answer, and it is decided once. Plant on a slope or a rise where cold air drains away downhill, not in a hollow or against a solid barrier that traps it. Avoid the warmest south-facing wall, which pulls the plant into growth ahead of the safe date; a cooler north or east aspect that holds it dormant a fortnight longer is the safer bet. Delay winter pruning until the end of dormancy where you can, since early pruning can nudge bud break forward. Keep the trunk and lowest arms wrapped or shielded through the first few winters. And when a freeze is forecast onto tender growth, cover what you can reach - floating row cover or old sheets thrown over the lower framework overnight and taken off in the morning genuinely saves crops.

Treat: There is nothing to spray and nothing to cut in a hurry. Wait - blackened growth looks fatal within a day, but the buds behind it are often alive, and you cannot tell which wood is dead until the plant pushes again a few weeks later. Once regrowth shows, prune back to live wood, water and feed lightly to support the second flush, and accept that this flush usually carries little fruit. Do not fertilize heavily to force it, which only produces soft growth that hardens off late. If the same plant is caught two or three years running, the site is wrong rather than the plant: move it to higher ground, or plan on covering it every spring.

This is the single reason a winter-hardy vine still fails to crop in the North: -25F in January is no trouble at all, and 29F in late April is a disaster. Arctic kiwi (A. kolomikta) breaks bud earliest of any kiwi and is the most exposed of the lot.

Japanese beetles are metallic green-and-copper beetles about half an inch long that emerge in early summer and feed for six to eight weeks. They feed in aggregating masses - one beetle's feeding releases a scent that draws in more - so a plant goes from untouched to covered in a couple of days. They chew the soft tissue between the leaf veins and leave the veins standing, so the leaf ends up as a brown lace skeleton, and they shred open flowers and sometimes ripening fruit as well. They work the sunniest upper parts of a plant on warm afternoons. The white C-shaped grubs spend the rest of the year in turf and pasture soil eating grass roots, and the adults then fly in from wherever they hatched, which can be some distance away.

Watch for: Clusters of shiny metallic beetles massed together on the upper, sunniest foliage and down inside open blooms, heaviest on warm sunny afternoons from around late June. Leaves reduced to lace, with the veins left intact and the tissue between them gone - unmistakable, and quite different from the ragged chewing of a caterpillar. Ragged, chewed petals and blooms that never open properly. Beetles that let go and drop straight to the ground when you disturb the plant. Feeding damage on ripening fruit, on the plants they also take fruit from. Whole branches going brown and lacy at the top of a plant while the shaded lower growth stays untouched.

Prevent: Hand-picking is genuinely the main defense in a home garden. Go out in the cool of the morning while the beetles are sluggish, hold a tub of soapy water underneath, and knock them in - they drop when disturbed, so most fall straight into it. Do it daily through the flight: because the beetles call each other in, taking them off early stops a plant becoming a beacon. Do not put pheromone or lure traps anywhere near the garden - they demonstrably pull in far more beetles than they catch. And do not count on lawn grub control: milky spore has performed poorly and inconsistently in field trials across most of the US, and treating your own turf does not reduce the adults feeding on your plants, because they fly in from surrounding properties. Where it is practical, row cover or netting through the peak flight excludes them outright. Otherwise riding out the six-to-eight-week wave is a legitimate strategy, since most established plants absorb the damage.

Treat: Persistent morning hand-picking into soapy water is the most effective home control there is, and on a vigorous established plant the damage is usually cosmetic and needs nothing else. Neem deters feeding rather than killing, and has to be reapplied. For heavy pressure, spinosad or a targeted insecticide labeled for the plant will work - but time any spray away from bloom and apply it at dusk to protect bees, and observe the pre-harvest interval on anything you eat. On flowering plants, some gardeners simply shear the blooms off for a couple of weeks and let the plant rebloom once the wave has passed, which removes the lure as well as the damage. Young plants and young trees are the ones worth defending: a mature tree or an established vine tolerates several weeks of leaf loss without lasting harm.

The most conspicuous pest on hardy kiwi in the Northeast and Midwest, lacing the big leaves through July. A mature vine grows straight through it; a first- or second-year vine being trained to a trunk cannot spare the leaves, so that is the one worth hand-picking daily.

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.

Deer strip the new shoots off establishing vines and can set a young hardy kiwi back years or kill it outright. A tall trellis lifts the growth out of reach as the vine matures, so the vulnerable period is the first couple of seasons - the same cage that keeps cats off the base is the obvious place to start.

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.

Kiwiberries are grape-sized, soft and sweet, and a small vine can be cleared in a couple of days. The practical answer here is often not netting a huge vine at all but picking the whole crop firm at black seed and ripening it indoors, which takes the food away before the birds commit to it.

Scale insects are sap-suckers that spend most of their lives immobile, fixed to a stem, twig, or leaf underside beneath a waxy or shell-like cover. They look far more like bumps, blisters, or crusty encrustations than like insects, which is why an infestation is usually well established before anyone notices it. Soft scales excrete large amounts of sticky honeydew that drips onto everything below and grows a black sooty mold - and those blackened leaves are often the first thing a gardener actually sees. Armored scales produce no honeydew but sit under a hard shield that protects them from most sprays. They spread as tiny mobile crawlers in the weeks after hatching, which is the only stage that moves and the only stage that is easy to kill. Populations build on stressed plants, on crowded shaded growth, and above all on plants kept indoors in dry, still air over winter.

Watch for: Rows of small brown, tan, black, white, or waxy bumps along stems, twigs, leaf midribs, and leaf undersides that do not brush off but can be scraped loose with a fingernail. A sticky shine on the leaves - and on the floor, table, or path beneath the plant - that later turns black with sooty mold. Ants running steadily up and down the stems, since they farm and defend scale for that honeydew; often the first sign anything is wrong. Yellowing leaves, weak thin growth, and dieback of individual branches or canes that are heavily encrusted. On fruit crops, scale covers and sooty mold directly on the fruit. Check the leaf undersides and the shaded inner wood, which is where colonies build up unseen.

Prevent: Inspect. Look over leaf undersides and stems regularly - on a crop you pick, every harvest is a scouting chance - and check every new plant thoroughly before you buy it, plant it, or set it beside anything else, because scale almost always arrives on a plant rather than flying in. Quarantine new houseplants for a few weeks. Keep plants unstressed and not over-fertilized, since soft, forced growth is what populations build on. Prune for airflow and light to open up the shaded inner growth where scale hides, and prune out heavily infested wood as routine maintenance - on anything that gets a hard annual pruning, that alone removes most of any buildup. Leave the lady beetles, lacewings, and parasitic wasps alone, since they normally keep scale down to nothing, and keep ants off the plant where you can, because ants protect the colonies from those predators. Indoors, avoid hot, dry, still winter air.

Treat: Horticultural oil is the main control: it works by smothering, so it has to coat the insects thoroughly - stems, twigs, and leaf undersides - and it usually needs repeating, because the waxy covering shields them and no single pass reaches everything. On deciduous woody plants a dormant-season oil smothers the overwintering stage while the leaves are out of the way, and timing a growing-season spray to the crawler stage, when the young are mobile and uncovered, is far more effective than spraying settled adults. On a small plant or a light infestation, scrub or wipe the scales off by hand, or dab them with a cotton swab of rubbing alcohol. Prune out and destroy badly encrusted wood rather than trying to save it. Wash off the sooty mold once the scale is gone - it lives on the honeydew, not on the plant, and stops once the supply does. Anything you spray must be labeled for the plant, and oils can burn delicate foliage, so test first.

Scale crusts the older canes and the trunk of an established vine. The hard annual winter prune removes most of any buildup as a side effect, and a dormant oil on the remaining framework smothers what is left; it is rarely serious on a well-pruned, unstressed vine.

Several Actinidia species contain compounds close enough to those in catnip that cats respond to them the same way, and the reaction is strongest to young wood and to freshly cut or bruised stems. Cats roll on the base of the vine, bite and chew the canes, rub against them and shred the bark, and a determined neighbourhood cat can reduce a first-year plant to a stub over a few visits. Arctic kiwi (Actinidia kolomikta) is the worst affected of the garden kiwis, along with the related silver vine; Actinidia arguta is attacked less consistently but is still well worth protecting while young. It is a nuisance rather than a disease, and it stops mattering once the trunk is thick and woody and the growth is up out of reach - but the first year or two is precisely when the vine cannot spare the damage.

Watch for: A young vine flattened, bent or snapped off near the base, with the soil scuffed and the mulch scattered around it. Bark chewed, shredded or rubbed away in patches on the lowest foot or two of stem, and shoots bitten off cleanly and left lying rather than eaten. Fur caught on the stem or the stake. Cats visibly rolling on or lying against the base of the plant. Damage that arrives in bursts - nothing for weeks, then a wrecked vine overnight - and that concentrates on newly planted or freshly pruned vines, because cutting releases the scent. On older plants, rubbing and bark loss at the trunk while everything above the first few feet is untouched.

Prevent: Cage the base. A cylinder of wire mesh or hardware cloth around the lower stem, held off the wood and pegged down so it cannot be shoved over, is cheap, permanent, and the only thing that reliably works - leave it on until the trunk is thick and woody. A ring of prickly prunings or coarse gravel over the root zone helps at the margins. Train the early growth up and tie it in rather than letting it trail at ground level where it is easy to reach. Where you have the choice, put a newly planted vine somewhere cats do not routinely patrol, and expect the heaviest pressure straight after planting and straight after a pruning.

Treat: Protect first, assess afterwards. Get a guard around the base the moment you see damage, because a cat that has found the plant will come back to it. A vine chewed off above a live bud usually regrows strongly if the roots are sound, so cut cleanly back to good wood, water it, and train the strongest new shoot up the stake as a replacement trunk - you lose a season, not the plant. A stem chewed through below every remaining bud is lost. Repellent sprays and scent deterrents work for a while and then stop, so treat them as a supplement to a physical guard rather than a substitute for one.

Worth taking seriously on Arctic kiwi in particular, and worth doing at planting rather than after the first loss - a wire guard around the base for the first two or three years costs almost nothing and is the difference between a vine and a stub.