The Japanese maple tree ( Acer palmatum ) is a slow - growing mintage that reaches a maximum height of only about 20 foot , though many cultivars are small . Japanese maples create wonderful focal point in garden or in groves , mixed in with other types of Sir Herbert Beerbohm Tree . They are more often than not hardy , but are susceptible to diseases that drift from inconsequential to deadly .
Cosmetic Ailments
Two disease that bear upon the appearance of Japanese maple tree diagram without endangering their life are tar spot and coal-black mold . Tar smirch appears on the leaves , commonly in mid - June , as icteric blot that eventually develop dark centre . The Plant Disease Diagnostic Clinic at Cornell report that tar spot is a fungal plague that rarely have serious harm , but extreme infestation can make massive leaf drop .
Sooty mould is a subaltern infestation that attacks trees weakened by sucking insect like aphid . The mold is dark Zane Grey and velvety , and usually appears on the leaves . The Rhode Island University Landscape Horticulture Program ( RIULHP ) notes that this disease almost never vote down the tree outright , but it is exceedingly unsightly and indicative of a potentially more serious job .
Treating Cosmetic Diseases
To control tar berth , you need to rake up the affected leaves in the fall and destroy them . Some fungicides can also avail , but because you have to implement them carefully and evenly , Cornell does n’t recommend them as a first railway line of defense .
RIULHP recommends treating sooty mold in two stair : operate the insect infestation by utilize an insecticidal soap or a stronger chemical substance remedy . Then blast the leaves of the maple tree with jet of weewee , to wash aside the mold .
Serious Ailments
Several different funguses can cause anthracnose , which shows up as browned spots on the leave-taking that spread out along the vein or as irregularly mold splotches on the leaf . The Alabama Cooperative Extension Service ( ACES ) says anthracnose is peculiarly dangerous to Japanese maples because it can cause the tree to lose all its leaves , which spread out the door for other more serious infestations . tree plant in wet , lovesome climates are especially prone to this fungus .
Untreated anthracnose can eventually make cankers on the tree ’s limb and trunk . Cankers are dead area can get until they gird the tree trunk or branch and defeat it . On Japanese maple , cankers look tan or grey compared to the usual red color of healthy branch .
Treating Serious Diseases
ascertain anthracnose by graze up and destroy all the blighted leave , rather before the tree starts to put out new leaves in the spring . fecundate and water the tree diagram munificently to help it recover .
To control pestilence on twigs or limb , prune out any limbs that have the lesions and discard the trimmings .
Potentially Fatal Diseases
Another deadly disease that attack maple is verticillium wilt . Also called maple wilt , this disease originate with Verticillium dahliae , a fungal infestation in the soil that the Oregon State University Extension ( OSUE ) describe as " almost impossible to eradicate . " Once the tree diagram engross the fungus through its roots , the fungus block the flow of water into the Sir Herbert Beerbohm Tree while producing toxin that make the leaves of the tree on the spur of the moment wilt and drop . Some trees die almost immediately , while some manage to last for several years .
Coping with Maple Wilt
Treating the disease is rarely successful , so the best way to avoid it is to have your garden grunge prove for the presence of Verticillium dahliae before you plant a maple . you’re able to buy a soil testing outfit at a local nursery or get it tested through your state agriculture department or county extension military service . Microsclerotia in the dirt should be see as a potential disease risk of infection .
To prevent the fungus from spreading , remove and incinerate any touched limbs . OSUE reports that nurseryman have sometimes manage to eliminate the fungus by mixing Italian rye grass clippings into the territory and track it with credit card sheeting for three months late in the summer .
