 |
 |
ANTHRACNOSE
Anthracnose is a common landscape disease caused by a fungus. The pathogen is in the vascular part of the plant. It commonly appears in spring and early summer during periods of high moisture. There are many potential host plants for this disease. Most commonly landscape impact from this is found on dogwood and sycamore trees. Treatment should be an integrated approach involving watering practices, fungicide treatment, pruning, and fertility monitoring.
|
|
 |
APPLE SCAB
Apple scab can really harm the appearance of ornamental apple and crabapple trees. Like most plant diseases, it is caused by a fungus. Apple scab becomes active on young foliage and fruit early in the spring. It is more active when there is more water available and with warm temperatures. Initially there are dark spots which appear on leaves. These can grow. Trees which are highly susceptible to apple scab may actually lose much of their foliage by mid summer due to this disease. This of course can weaken a tree. Fungicide applications beginning in the spring will help to manage this disease. Removal of fallen leaf debris is recommended to reduce potential new infections. If you want to buy a new crabapple tree for your landscape, it is advisable to select a plant variety which will be resistant to apple scab disease.
|
|
 |
BLACK KNOT
Black knot is an ugly looking fungal disease which is found on trees such as cherry and plum. The pathogen is in the affected twig and as it grows it produces a dark swollen “knot” on the twig or branch. Management of black knot is very difficult. Affected branches cannot be saved. The best strategy is to try to protect the remainder of the tree through site sanitation, judicious pruning, and fungicide application.
|
|
|
CEDAR APPLE RUST
This is a fungus caused disease which affects cedar or juniper as well as apples and hawthorns. It is interesting because it is an alternate host disease. The fungus needs two completely different host plants to complete its life cycle. The initial infection is on cedar trees or juniper. It generally is not a serious problem there, but it produces an interesting red/orange glob with protruding horns on twigs. The fungus spores then arrive at a susceptible host such as a crabapple and develop red/orange circular spots on leaves. These can get large and extensive, resulting in partial or full defoliation. This can be managed with spring and early summer fungicide sprays. More effective management would be to remove one of the needed host plants from close proximity with each other. Look for rust resistant trees when purchasing new plants.
|
|
|
CROWN GALL
Crown gall is a soil born disease caused by a bacteria. It can affect plants such as euonymus and rose. Most commonly it is found on the low creeping euonymus. A round woody brown growth appears on a twig and surrounds it. It can result in twig dieback This disease is not controllable except through pruning.
|
|
 |
DUTCH ELM DISEASE
This disease is from a fungus which was introduced to our region from Europe. It has resulted in severe decline and death of many large elm trees. The fungus is carried to host plants by a bark beetle. Efforts have been made in various areas to save valuable mature elms with tree injections. This can work if the tree has enough vigor. There are also efforts being made to breed elm trees which will have resistance to this damaging disease.
|
|
 |
HORSE CHESTNUT LEAF BLOTCH
This is a fungus disease affecting horse chestnut trees in the eastern U.S. It starts in spring as small light brown spots which can grow. Over the time the leaves turn brown and distorted. Leaves may then fall from the tree. This can cause weakening of the tree. It is also unsightly when a tree is heavily affected. Fungicide sprays can help control the visible effects of the tree to improve aesthetics in a landscape. Sanitation by removing fallen leaf debris helps to reduce potential new infection. Pruning to open the foliage canopy to air movement and light penetration will help to minimize conditions which would favor disease development.
|
|
|
JUNIPER TIP BLIGHT
There are two primary fungi which result in similar damage to junipers in the landscape. They are Kabatina and Phomopsis. This disease appears on junipers in the spring as dead brown tips of branches. The life cycle of each of these pathogens is a little bit different, so fungicide spray timing would vary. Dead tips can be pruned away and removed from the planting location. Dead tips on juniper in spring should be inspected to determine the actual cause. It can also be winter injury, salt damage, or die back due to rodent activity.
|
|
|
LEAF SPOT
Leaf spots are probably the most common diseases on landscape plants. There are leaf spots which can affect many of them. They are caused by fungi and can be most active and troublesome during periods of warm wet weather. On plants affected, fungicides will usually provide good control. Also, improvements to sun exposure and air circulation can reduce the impact.
|
|
|
POWDERY MILDEW
Powdery mildew is a very common fungus disease which affects foliage of several landscape plants. Some of the more common hosts would be lilac, dogwood, and sycamore. It appears as a powdery white or grayish white covering on leaf surfaces. This can be unsightly, but often does not do serious damage to the tree except to reduce sunlight getting to the leaf. In some cases it can be very serious. Control with fungicides is generally successful. Also, improvements to air circulation can reduce advance of the fungus.
|
|
|
SPHAEROPSIS OR DIPLODIA TIP BLIGHT
A fungal disease which can harm pine trees. It causes browning and dieback from the growing tips of branches. During favorable weather conditions, this disease can move to nearby pines. Fungicide treatment can be helpful. Timing of treatment is very important.
|
|
 |
VERTICILLIUM WILT
This and other vascular wilt diseases is caused by a fungus pathogen which is active in the plant internal conductive tissue. As it develops and grows, it obstructs internal movement of water and nutrients in the tree. This causes gradual weakening and dieback of branches, known as flagging symptoms. A cross section sample of an infected branch shows discoloration. Treatment is difficult since the pathogen is inside the tree. Trunk injection of fungicides, pruning, and maintaining plant vigor can get positive results if decline is not too severe before treatment.
|
|
|
CANKER DISEASES
Some of the most damaging and common diseases found on trees are the cankers. There are several fungus pathogens which can produce these problems on various host plants. Treatment is difficult and often not reliably available. These pathogens get into a tree branch or trunk and produce deformities on them. They may be swollen, cracked or sunken in appearance. A major symptom which would first be noticed is general decline of a tree in whole or in parts.
|
|
|
LACE BUGS
Lace bugs are small insects which will be found on the underside of leaves of affected plants. The damage they cause looks like little brown dots on the leaf. This is called stippling look. They feed by sucking juice from the leaves from the underside. Usually they are active in the summer and into the fall. If there is damage you can usually find them on the leaf along with other signs of their presence and activity. They may be very well controlled by insect control sprays. Lace bugs are most commonly found as a problem on Japanese Andromeda and on azaleas.
|
|
|
APHIDS
one of the most common and widespread insect pests is the aphid. We can find these on many plant hosts during most of the growing season. They feed by sucking plant juices from foliages or twigs. Once detected, they are not difficult to control. Insect control sprays are effective on the aphids. Sometimes they can be swept off of plants with a stream of water, though some will return. Damage to plants appears as reduced vigor and as distortion of foliar growth.
|
|
|
BIRCH LEAF MINER
This insect causes injury to birch trees as the larva stage feeds inside the leaves. As it feeds it causes irregular browning, which may increase to the point of complete killing of leaves. Since it feeds internally, a systemic insecticide would be needed to control the larva. There is a predatory insect which attacks the leaf miner and often helps reduce the impact of this pest. There are several other leaf miners found in landscapes. They feed in similar patterns. Common ones attack holly, lilac, and arborvitae.
|
|
|
BORERS
Borers can be very destructive in landscape settings. The larva stage of the insect is active beneath the bark of the woody plant. This zone beneath the bark is the most important for growth and conduction of water and nutrients. When the insect interrupts the tree function, serious permanent dieback occurs. These insects are difficult to control. Tree injection is the most effective method for direct control. To help avoid borer attack, keep your trees as healthy and vigorous as possible. These insects are opportunistic, seeking out weakened trees to infest. Borers are common pests of birch, peach, dogwood, pines, lilac, rhododendron and several others.
|
|
|
CATERPILLARS
Leaf feeding caterpillars are common insect pests found during the growing season. Most are the larval stage of a moth or butterfly. When they occur in large populations, their leaf chewing causes extensive injury to trees and shrubs. Recurring caterpillar damage can result in significant weakening of our plants.
|
|
|
SAWFLY
This pest problem is also a foliage feeder. They look similar to the caterpillars in the larva stage which causes the plant injury. The adult in this case is a small wasp. The sawflies tend to feed in groups on the host plant. The most important host plant in our area is the hard pines. A large sawfly population can kill back the ends of branches.
|
|
|
SCALE
Scale insects on plants spend most of the time in one spot under a covering they produce for protection. They feed by the piercing sucking method. The insect does have crawler stages which are vulnerable to insect control sprays. They are also one of the main targets of spring dormant oil spray treatments. A scale population can increase rapidly under favorable conditions. Sometimes a sooty mold on a plant, or objects below a plant will be an indicator of scale activity. White mealy bugs can also cause sooty mold. They can cause plant weakening and dieback.
|
|
|
BLACK VINE WEEVIL
This insect causes injury to landscape and nursery plants. The adults weevil feeds on the host plant foliage at night. The larva is a grub which feeds on the roots of the same host plant. Feeding can be very destructive. Adult feeding appears as notches on leaf margins of host plants. Common host plants include taxus, rhododendron, and euonymus.
|
|
|
JAPANESE BEETLE
This is a common and very familiar insect pest. The adult beetle feeds voraciously of many landscape plants. The larval grub is a serious turf pest. The adult is usually active in the mid summer period. They feed on leaves, leaving the vein structure which is called leaf skeletonizing. Insect control sprays are effective for control.
|
|
|
SPIDER MITES
These are very small arachnids which feed on the underside of leaves. They cause a stipling damage pattern. Leaf discoloration and eventual leaf death occurs. Under favorable conditions, the spider mite can increase in numbers very quickly. Pesticides may be applied as needed for management of this pest. Sometimes natural predators will successfully keep the damaging mites in check. Many landscape plants are vulnerable to activity of certain mites. Common hosts would be hemlock, spruce burning bush, forsythia and others.
|
|
 |
BOXELDER BUG
This insect is not harmful to plants or people. It is considered a nuisance pest since it attempts to get into buildings late in the season when weather gets colder. Their life cycle is connected with the boxelder maples. Removal of those trees could reduce or eliminate any problem with these.
Contact Greener Lawns to Request a Quote or call 978-470-3111
|
|
