Creating Healthy Landscape and Tips to Choose plants
Creating Healthy Landscapes
When a plant looks unhealthy or has been injured by an insect or a mite, often our first impulse is to apply a pesticide. But that solution might be a waste of time and money. Applying the wrong pesticide could destroy the pest’s natural enemies, which sometimes take care of the problem without any intervention. A better approach is to manage the health and beauty of trees, shrubs, and flowers with minimal pesticide use. Some call this method integrated pest management (IPM); others call it to plant health care (PHC). It involves looking at the total landscape; identifying the insect, mite, disease, or growing condition that appears to be causing a problem; and if any action needs to be taken, choosing from a variety of sound management strategies. This approach takes into account that only 3 to 5 percent of insect species are harmful and that most pests have natural enemies such as birds, toads, and beneficial insects to keep them in check. Penn State Cooperative Extension and well-informed horticulture professionals in the landscape and nursery business suggest using IPM practices. The five steps outlined in this fact sheet will help you take better care of your landscape plants and evaluate the services of professional landscape maintenance companies.
five steps to take…
1. Choose Plants
Select plants that are suited to the conditions in your landscape. For instance, if the soil is acidic, choose plants that prefer acid conditions. If most of the area is shaded, then you need plants that prefer shade. Plants placed in the wrong location will not thrive and will be susceptible to many problems in the future. Select plant cultivars that are known to be less susceptible to insects, mites, and diseases. Also, consider growing plants that are native to your area or an area with similar growing conditions.
2. Plant with Care
Help plants get a good start by installing them correctly. Mistakes made when planting or when applying mulch can result in weakened plants that are prone to problems.
3. Promote Plant Health
Healthy, vigorous plants are less vulnerable to damage caused by insects, mites, and diseases. Provide the best growing conditions by testing the pH and nutrient level of your soil, preparing the soil well before planting, and then using fertilizers only as needed. Water plants regularly until they become established. Use mulches correctly and follow proper pruning recommendations.
4. keep plants well-groomed
Debris that builds up in the landscape may harbor pests and plant diseases. Remove dead or dying plants. Rake and remove leaves that drop off plants. If a branch is broken or diseased, prune it. Use organic mulches that have been composted properly. Apply a layer no deeper than two or three inches, making sure the mulch does not touch the trunk or main stem of the plant.
5. Monitor Pests
Inspect plants regularly for insects, mites, diseases, or any unusual changes in appearance that might indicate a problem. Accurate identification of the cause is essential for evaluating the situation and determining what, if any, management tactics are needed. Be aware that if a pest shows up, natural enemies that prey on it often appear as well. To monitor the health of plants in a landscape, you also must be able to recognize these beneficial insects. You may need to tolerate some plant injury before populations of beneficial insects and mites build up enough to keep a pest in check. It is important to understand the biology of many different plants. Additionally, knowing how pests and plants are affected by the weather is important. Professionals who have this knowledge often are called IPM scouts or PHC technicians. Whether you develop this expertise for your location or hire a skilled professional to provide assistance, you soon will realize that the knowledge needed to monitor the health of a landscape is almost as sophisticated as that required of a physician.
How the Program Works
This approach is based on an understanding that pests are part of the environment and that trying to eradicate them is usually unrealistic. The idea is to manage the situation by keeping plants healthy, monitoring conditions in the landscape, encouraging natural pest controls, and if a pest is detected, determining whether damage levels are high enough to require treatment. If treatment is needed, physical or biological controls are recommended first. As a last resort, conventional pesticides may be used judiciously to manage the problem.
Pest Management Methods
Pests can be removed from plants physically. For example, some species of aphids can be removed with a forceful water spray, and bagworms can be picked off infested plants. Traps and barriers can be used to keep insects away from plants. Some diseases are best managed by physically removing the infected plant part.
Often, pests can be controlled by enlisting the help of their natural enemies. These strategies sometimes are called biorational. For example, lady beetles, one group of beneficial insects, eat aphids and other soft-bodied insects. In an IPM program, grounds managers may encourage populations of beneficial insects and even will introduce them into the landscape
Another biorational method uses a naturally occurring bacterium called Bacillus thuringiensis (Bt). Bt produces a protein that is toxic to some insect pests but harmless to most other organisms.
Sometimes pesticides provide the best control. In many cases, environmentally safe pesticides such as horticultural oil or insecticidal soap can control pests. In IPM programs, the least toxic pesticides are used first. Apply registered pesticides according to label directions and at a time when the pest is most susceptible. If possible, apply them only to the affected parts of infested plants.
When monitoring plants in a landscape, you should keep records of each plant inspection. Observations should include the date, time, weather, major problems on each plant species, the presence of beneficial, management decisions made, control techniques used, and an evaluation of control effectiveness. Whether you maintain your own landscape plants or hire a professional, you should ensure that good records are kept during the growing season. A landscape management service that does not keep good records is not providing an IPM program. Records are invaluable for management not only during the current season but also for anticipating future problems. Records also may demonstrate the need to move or replace a plant that has persistent, high-maintenance problems.
benefits of an IPM program
• Beautiful, healthy landscape plants
• Long-term effectiveness
• Use of least-toxic pest and disease management methods
• Lower cost over time
Tips to Choose plants
To create and maintain a healthy landscape, choose plants that are suited to the conditions in your yard. Plants placed in a location that meets their requirements usually thrive without requiring a lot of attention. Plants in a location that does not suit them will be stressed, vulnerable to attack from pests and diseases, and may require more care. For example, rhododendrons are popular landscape plants because they are evergreen and offer a spectacular display of flowers in the spring. Most rhododendrons require good soil drainage, some shade, and acid soil conditions. If planted in a poorly drained area, they are likely to develop root rot diseases. In full sun, they often become infested with lace bugs and other insects. If they are planted in alkaline soil, they are likely to weaken and die. If the conditions in your yard are not right for rhododendrons, you should consider choosing another plant. Follow the steps below in selecting new plants for your yard. When you have gathered the information described in these steps, you also will be able to evaluate problems of existing plants in your landscape.
1. Know the Conditions in your Landscape
How cold does it get during the coldest winters? How hot does it get in the summer? What is the average rainfall in your area? Observe how many hours of sunlight each particular site receives and the direction of the prevailing winds. Determine your soil’s texture and drainage, and have the soil tested through your local garden center or extension office. The soil test will determine your soil’s nutrient level and pH, a measure of acidity or alkalinity.
2. Know the Requirements of Landscape Plants
Learn the specific needs of a new plant before you buy it. Will the plant be able to survive the winter at your location, or will it need protection? Does it require more rainfall that occurs in your area? Does this plant require soils to have a pH within a narrow range? How much space will this plant require maturity? Does it have a shallow root system that will interfere with your sidewalks or lawn? Does it shed pollen or fruit, or does it have thorns that will be a nuisance in the location where you plan to place it? Some insect pests and diseases occur when certain plants are grown near each other. One common example happens when eastern red cedar (Juniperus spp.) is grown near apple or crabapple trees. Cedar-apple rust is a disease caused by a fungus that requires two different host plants to complete its life cycle. It overwinters on the red cedar and releases spores in the spring that infect apple leaves. In the fall, it produces spores that infect cedar. When either host plant is absent, the fungus cannot complete its life cycle. A similar disease problem occurs when junipers are planted near quince, Hawthorne, or serviceberry. Thorough research and questioning will enable you to avoid such troublesome plant combinations. Identify existing plants in your landscape. If any are not doing well, find out what their preferences are. You may discover that they need to be moved to a more compatible site or removed altogether.
3. Choose Plants that are Well Adapted to your Site
Of all the choices you make in selecting plants, this is the most important. Create a landscape that does not depend on irrigation, special seasonal protection, and constant artificial control of diseases and pests. Native plants occur naturally in a region without being introduced or planted there by humans. Trees, shrubs, and other plants native to a particular locality usually can be relied on for their cold tolerance and longevity in the area. Even though a plant is native, however, it still may have problems, especially if it is placed in a location that does not meet its requirements. For example, white pine is a beautiful native pine, but if it is planted in an area with poor drainage, it probably will not thrive in that site. Also, white pine is very susceptible to injury by salt, so it should not be planted along a highway that is treated with deicing salt in the winter. Exotic plants are those introduced from another area; however, the growing conditions of that area might be very similar to those of your location. Before choosing an exotic plant, make sure your growing conditions will meet the plant’s requirements. Sometimes, exotic plants are more resistant to pests than are their native relatives. For example, Cornus kousa, an exotic dogwood that was introduced from the Far East, is less susceptible to infestation by the dogwood borer than is Cornus florida, the flowering dogwood, one of our native species. Your local extension office can provide lists of plants recommended for a specific area and advise you if plants you are considering have problems.
4. Select Resistant Varieties
If a plant is highly susceptible to a certain disease, plant breeders work to develop varieties with built-in resistance. Many disease-resistant varieties, or cultivars, are available from your local nursery. Even if you have to search farther to find them, you will be rewarded in the long run because resistant varieties, when managed properly, will thrive where susceptible ones will not. Flowering Crabapple (Malus spp.) is a popular small tree for residential landscapes, mainly because few other trees or shrubs approach its beauty when in full flower. The species is plagued with disease problems such as scab, fireblight, cedar-apple rust, and powdery mildew. Disease-resistant flowering crabapples have been developed; a list is available from your local extension office. You may have a favorite shrub or tree that is susceptible to problems but for which no resistant variety has been developed. In this case, you usually can find a more rugged substitute with a similar bloom color, bloom time, fall foliage, bark, or whatever characteristic attracts you to the plant.
5. Select High – Quality Plant Material
Once you have become familiar with your landscape’s conditions and have learned about the plants that you plan to install, the next step is to purchase them. Buy healthy, robust, thriving plants. They will become established more easily and will be less likely to introduce a pest or disease problem in your landscape. Remember that “bargain” plants may have a lower rate of survival. These plants usually have been sitting around for months and may have been neglected. Choose healthy plants that have no signs of harmful insects or their damage. The bark should be free of defects, splits, or soft areas. The soil surrounding the roots should be moist but well-drained, and the roots should not be growing in circles around the root ball or protruding from the drainage holes. The root ball should be big enough to support the plant. Before you buy new plants, make sure you are ready to plant them as soon as they arrive. Use proper planting methods for your new plants and water them regularly until the plants become established, at least through their first season. For current planting recommendations, see the Plant with Care fact sheet in this series.
Your local library, garden center, and bookstore are good sources for books about plants. Lists of recommended shrubs and trees for sites with acid or alkaline soil, poor drainage, dense shade, full sun, and so on are available from your local extension office.
Table of Contents
- 1 Creating Healthy Landscape and Tips to Choose plants
- 1.1 Creating Healthy Landscapes
- 1.2 How the Program Works
- 1.3 Pest Management Methods
- 1.4 keeping records
- 1.5 benefits of an IPM program
- 2 Tips to Choose plants