Ornamental Landscape Plant
Pests and Diseases
Taking a minute to learn about tree and shrub pests and diseases is all you need to keep your landscapes and plantings healthy and thriving. When you take into account harmless and beneficial insects, an ounce of prevention is worth a pound of cure.
Landscape Plantings, Pests, and Diseases
Well-maintained, healthy plants are less susceptible to pests than stressed or injured plants, and they are better equipped to shrug off disease.
To keep your landscape healthy, water each tree and shrub according to its needs, avoiding either overwatering or underwatering. An automated drip irrigation system is a great help for applying the right amount of irrigation at the base of each plant and conserving water.
Make sure that there is good air circulation between and within plants, since this will protect against fungal or bacterial outbreaks.
Strive to keep your garden neat by removing weeds and debris—weeds weaken other plants by competing for water and nutrients, and fallen leaves, twigs, and debris makes homes for undesirable pests.
Make sure the soil’s pH is adjusted to suit the plant species being grown, and fertilize only as indicated by a soil test.
Scouting, Identifying, and Treating
One of the best things you can do for your plants’ health is to take frequent walks through your garden. Look carefully at each plant, keeping an eye out for discolored or tattered foliage or anything else that seems amiss. When you see something amiss, look more closely.
If there are signs of diseases or pests, refer to the advice on the GrownByYou pest symptoms and cure chart [See: Controlling Common Pests and Diseases].
Proper symptom identification is important. If still unsure, take a sample of the problem in a clean, sealed plastic bag to a Master Gardener or university extension office, or seek help from a nursery or garden center, where the staff can provide a diagnosis.
When you find specific pests in your garden, study all your options before taking action. About 90–95 percent of all insects found in home landscapes are either beneficial or harmless. It’s important to keep these useful insects alive so they naturally control outbreaks of harmful pests.
Even if pests are present, relax. Most plants take quite a bit of foliage loss or other damage without harm.
Try the environmentally safe practices of hand picking off any visible pests, knocking pests off a plant with a strong stream of water from a garden hose, or pruning out any diseased portions of the affected plant. Those actions may be all you need to do.
Don’t spread diseases around your yard. Always sterilize pruning tools and shears before and after use by dipping them in dilute bleach solution.
If an active infection is underway, treat them between cuts. Make the disinfectant by mixing household bleach containing sodium hypochlorite with water at a ration of 1 part bleach to 12 parts water.
Not all simple cures solve serious problems. When you meet a tough infection or infestation, apply stronger controls such as horticultural oils or insecticidal soap solutions. Both are available at nurseries and garden centers.
(Any control you use in your garden should list on the label the specific disease or pest you’re treating, and should be carefully applied in accordance with the manufacturer’s printed instructions.)