Toyon

Young plants are the vulnerable ones and want a cage for two or three years. Under heavy pressure expect a browse line about five feet up and a bare-legged shrub - which is often the moment to give in and limb it up deliberately into a small tree.

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.

What still kills it is frequent shallow watering in warm soil, a daily lawn sprinkler pattern, or a low spot that ponds through winter. Water deeply and rarely, keep the crown proud of the soil, and plant on a slope or slight mound in heavy ground.

Wilting in the middle of the day on a plant whose soil is damp - the classic tell, and the reason people water a rotting plant and finish it off. Leaves yellowing from the bottom up, dull off-color foliage, and growth that stalls for no visible reason. Whole shoots, or one side of the plant, collapsing while the rest still looks fine. Soft, dark, or mushy tissue at the base of the stem or at the crown, sometimes with a sour smell. Lift a failing plant and look at the roots: healthy ones are firm and pale, rotted ones are brown or black and slimy, and the outer layer slips off between your fingers leaving a thread of core behind. Seedlings that topple over at soil level are the same problem, called damping-off.

There is no cure for tissue that has already rotted, so act on the conditions rather than looking for a spray. Stop watering at once and fix the drainage - open up compacted soil, or move the plant to a raised, sharply drained position or a container. Lift a badly affected plant, cut away every soft dark root and rotted section with a clean blade back to firm pale tissue, and replant only the healthy parts into fresh free-draining soil or mix. Often the better move is to give up on the plant and save its offspring instead: cuttings, offsets, or divisions taken from firm healthy growth root readily and give you a clean start. Bin the rotted material rather than composting it, and correct the drainage before you replant, because the rot comes straight back in the same wet spot.

Drainage is the whole defense. Match the plant to the site first - something that wants sharp drainage will not survive heavy clay or a low, water-collecting spot however well you tend it. Where the ground is heavy, plant on a raised bed, berm, or slope, or grow in a container. Set plants at the depth they were already growing, since burying the crown or the root flare is a common cause of rot, and keep mulch pulled back a few inches from the stem base instead of piled against it. Water the soil rather than the calendar: check that the top inch or two is dry before watering again, cut back hard in cool weather and winter dormancy, and never leave a pot standing in a full saucer. Do not plant or dig in soggy ground, and go easy on rich amendments for plants that want it lean. Rotate annual crops, and start with clean healthy plants and fresh mix.

Root rot is not one organism but a group of soil fungi and water molds - Pythium, Phytophthora, Fusarium, Rhizoctonia and others - that sit harmlessly in most soils and only turn destructive when the ground stays saturated. Waterlogged soil drives the air out, the roots suffocate, and the weakened tissue is invaded and goes soft, brown, and stringy. Because the damage is underground you usually see it first as something that looks like drought: wilting, yellowing, stunting, a plant that does not respond to being watered. Overwatering, heavy compacted ground, a low spot that collects runoff, a pot with no drainage or a saucer left standing full, and cold wet soil in winter are the usual causes. Once roots have actually rotted there is no cure - this is a problem you prevent rather than treat.

It shows up after a warm, wet early summer as blackened flower clusters and hooked shoot tips. Cut well below the damage in dry weather, sterilizing between cuts. It is also the reason not to plant toyon hard against an apple, pear or quince where blight is common.

Sudden wilting and blackening of blossoms and shoot tips that look burned rather than diseased, shoots bent over into a hook, dark sunken cankers on limbs, and amber bacterial ooze on the bark in warm humid weather.

Cut strikes out at least 8 to 12 inches below the visible damage, sterilizing the saw or pruners between every single cut, and remove and destroy the prunings rather than leaving them lying. Cut cankers out in dry dormant weather. Copper or biological sprays at bloom help in high-pressure areas - use only a product labeled for the crop you are treating, follow the label exactly, and observe the pre-harvest interval before you pick.

Where a resistant option exists for your crop, variety choice matters more than any spray - check before you buy. Avoid heavy nitrogen and hard pruning, both of which force the soft succulent growth the bacteria enter through, and never prune or work the plant in wet weather. Keep susceptible hosts spaced apart rather than planted hard against each other, and do not prune two of them in the same wet spell.

A fast, destructive bacterial disease (Erwinia amylovora) of the rose family. It enters through open blossoms and soft shoot tips in warm, humid weather, then runs back down the shoot, blackening leaves and wood as though scorched and bending the tip into a telltale 'shepherd's crook'. From there it moves into limbs as dark sunken cankers, and it can kill a young tree in a single season. Apple, pear, quince, loquat, hawthorn, serviceberry and toyon are all hosts, and susceptibility varies enormously between species and between varieties.