Insect damage, fungal infections, fire blight or stony pit virus can cause black leaves on pear trees. Frost damage, spider mite or pear psylla infestations, blossom blast, pear scab or sooty mold cause leaves with black tips.Know More
Most often, leaves on pear trees turn black due to fire blight, a highly contagious bacterial infection. The culprit is the bacterium Erwinia amylovora. This disease not only attacks pear trees, but it endangers apple and crabapple trees as well.
Fire blight is identified early on by spots on the trees with bark that oozes a light tan material. This ooze leads to streaked bark. If left untended, the bacteria first infects open flowers and young fruit, which turn black. Eventually the leaves turn black and die as well.
Fire blight grows best during rainy weather with temperatures between 75 and 85 degrees Fahrenheit and attacks the growing wood first. In order to prevent fire blight, a gardener needs to avoid over-fertilizing or over-pruning the tree. These two actions promote growth, which creates the ideal home for the bacteria. A gardener also needs to cease watering the tree as it blossoms. If fire blight occurs, the infected growth needs to be pruned away and new blossoms sprayed.Learn more about Trees & Bushes
One difference between a Japanese maple tree and an evergreen is that the maple is a deciduous tree and loses its leaves in winter while the evergreen is coniferous. The Japanese maple has feathery red-purple leaves that turn bright red in the fall before dropping off the tree. Evergreens retain their leaves and color all year, according to Colorado State University Extension.Full Answer >
The best fertilizer for pear trees is a balanced 10-10-10 formula of nutrients. This fertilizer blend is made of equal amounts of nitrogen, phosphate and potassium.Full Answer >
When the leaves of a citrus tree turn yellow, the tree usually has a mineral deficiency or is diseased. Mineral deficiencies typically are soil related and can be fixed by adjusting the pH. Over watering can lead to diseases which cause yellow leaves and rotting. Excess sunlight also can cause yellowing and curling of citrus leaves.Full Answer >
Types of maple trees can be identified by the shapes and sizes of their leaves, their bark and their winged seeds, which are called samaras. They can also be differentiated by the habitat where they're found, their mature height and their shape.Full Answer >