|Leaf of eastern redbud
|Bark of eastern redbud
Hardiness Zones: 4 to 9
Height: 30 ft
Spread: 25 ft
Type: deciduous tree
Annual Growth Rate: 12 to 18 inches
Light: Full sun to shade
Moisture: Grows better in moist soil
Fertilizer: TreeHelp Premium Fertilizer for Redbud
|Cercis canadensis var. alba
The Redbud tree is a relatively small tree with spreading branches and a small short trunk. The Redbud is a poplar ornamental tree, which can be found in many gardens and streetscapes. The tree is one of the earliest flowering trees and is often used to add color to gardens.
The purple pink flowers of the eastern redbud appear all over the tree in early spring. The flowers are even produced on large trunks. Redbud has a yellow fall color and is shade tolerant.
The Redbud grows throughout much of the eastern United States and extends as far west as Texas, Oklahoma and Kansas.
var. alba - The flowers are pure white.
'Forest Pansy' - The new leaves are scarlet becoming maroon as they mature. The flowers are pink. This cultivar may not be as hardy as the species.
'Flame' ('Plena') - Double pink flowers appear at the same time as the leaves. Seldom sets fruit.
'Silver Cloud' - The leaves are variegated with pink and white. The plants are 12 feet tall and wide.
Treehoppers lay eggs under the bark of twigs. The insect itself is not seen but the white, sticky froth covering the eggs is quite noticeable (see image). The insect is seldom serious. Use Horticultural Oil in a dormant spray dosage to control treehoppers. The Horticultural Oil should be applied when the temperatures are between 35 and 85 degrees Fahrenheit.
Scale insects are small, non-mobile insects that attach themselves to the wood and sometimes the foliage. Scale is most common on the new tender woody growth. When adult scale is attached to the tree, it often appears as crusty or waxy bumps on the tree and is often mistaken for part of the tree’s own growth, but it is actually an insect. The scale sucks sap from the tree and causes the leaves to turn yellow and drop. Often a sticky substance can be found near the scale or on the leaves. This is a secretion from the scale called honeydew and often acts as an attractant for ants or as a growing source for sooty mold.
In the spring or mid-summer, small, almost invisible nymphs emerge from under the female shells and move to infect new areas of the tree. This is the only time in the life cycle of scale that the insect moves.
To effectively control scale insects and limit damage, Horticultural Oil should be sprayed on the tree. The Horticultural oil serves to suffocate the scale and eggs. In the spring or early summer if the crawling nymphs are present, spray the trees with [Bug Buster] to prevent the new nymphs from further infecting the tree.
Spider mites are an extremely tiny pest, and generally appear as a brown, red or purple specks on the underside of leaves. Mites infest leaves and cause the leaves to appear speckled with yellow spots or wilted and curled. A fine silken webbing can sometimes be seen on the underside of the leaves. Intense infestations during hot, dry weather can cause the leaves to curl and drop.
To confirm if the tree has a spider mite infestation take a close look at the undersides of the leaves for small insects, the size of ground pepper. You may need to use a small magnifying glass to adequately see the spider mites. Another way to examine for spider mites is to take a sheet of white paper, hold it under a group of leaves and give the leaves a few sharp taps to shake some of the spider mites loose. On the white paper the spider mites can be easily seen.
Spider mites damage the tree by sucking sap from the underside of the leaves. The bite marks appear as a yellow speckled pattern on the top and bottom of the leaf. As the season progresses and the temperature becomes hotter and dryer (above 70 degrees F.) the population of spider mites will increase exponentially and can rapidly defoliate a tree, especially if the tree is having trouble taking up water during drought periods. To control mites, spray the tree with Bug Buster. Be sure to spray the underside of the leaves as well as leaf crotches as this is where most spider mites and their eggs are found.
Dieback/Canker is the most destructive disease that attacks Redbud trees. It is first seen as a tree’s leaves wilt and turn brown. Often cankers can be seen on branches and twigs. The cankers can either be seen as visible cankers on the surface of the branches or as dark sunken areas with black centers.
The canker or dieback is caused by a fungus (Botryosphaeria ribis) which attacks not only the redbud but more than fifty other types of trees and shrubs. The disease is spread throughout the tree, or from tree to tree, by splashing rain and winds that move the fungus from diseased areas to healthy parts of the tree. The fungus then enters the tree through wounds or dying branches. The fungus gradually spreads out within the tree’s vascular system slowly blocking the tree’s vascular system and inhibiting its ability to transport nutrients and water. The result is a gradual dieback of branches as the flow of nutrients and water is cut off.
There is no effective chemical control for the canker. If canker is identified in a tree, prune out and destroy dead branches and infested areas. Be sure to make pruning cuts at least 3 or 4 inches below the canker, so that the cut is into healthy viable wood. After every pruning cut, be sure to properly sanitize the pruning tools so that the fungus is not transported on the tools and infects healthy parts of the tree.
An effective pruning and sanitization program can be helped with a fungicide spray program. Spray both the healthy and diseased sections of a tree with Liquid Copper during and shortly after periods of excessive rain. Using a fungicide such as Liquid Copper will not eliminate the disease but it can help slow the spread of the fungal disease to healthy trees.
Leaf spots can be a problem during wet weather. The spots appear as small brown or black spots on the top of leaves. Since the disease is rarely serious, no chemical controls are normally needed, however, in severe cases or to improve the look of the tree, spray the tree with Liquid Copper. The fungicide spray should be applied when the leaf spots are first noticed and again in about 14 to 20 days. The following spring, shortly after bud break, re-spray the tree with the Liquid Copper to ensure no over-wintering of the spot disease. Since the leaf spot fungus over winters in the fallen leaves and then re-infects the tree the following spring, it is important in the autumn to collect up and remove any leaves that have fallen to the ground.
Verticillium wilt attacks and kills redbud trees. Verticillium Wilt is a very common disease that attacks a large number of trees. It is caused by a soil-inhabiting fungus called Verticillium. The disease fungus can be spread by many methods including from plant-to-plant, through the soil, groundwater and often by infected pruning equipment that has not been properly sanitized. The disease normally enters the tree through the soil, but can also be introduced into a tree through a wound. Once in the tree, the fungus begins to spread throughout the tree’s vascular system, as the fungus level increases the tree’s vascular system becomes blocked preventing the tree from adequately moving water and nutrients throughout the tree.
The first signs that a tree has a Verticillium Wilt infection is the yellowing and then browning of leaves at the ends of some branches. Initially the yellowing and browning of the leaves is spotty throughout the tree and does not follow a uniform pattern. As the fungus begins to block the vascular system, the browning of leaves becomes more acute and more wide-spread. New leaves generally are either non-existent, undersized or yellowed.
As the disease spreads, the infected tree may slowly die, branch by branch over several seasons. The symptoms and severity of Verticillium wilt are much more harsh during droughts.
There is no chemical control for Verticillium Wilt however there are several steps that can be undertaken to help control the spread of the disease, as well as enhance a tree’s ability to control or even contain the disease. These include pruning, fertilizing and watering.
Prune and remove all dead wood. The pruning should be a few inches below the diseased area, so as to remove as much of the fungal concentrations as possible. When pruning do not remove branches that have recently wilted as they may reflush again in a few weeks or the following spring. When pruning be sure to properly sanitize the pruning tools after each cut.
Give the tree a very good fertilization with a slow release nitrogen. The TreeHelp Annual Care Kit contains an appropriate fertilizer for Redwood trees, as well as a Redwood mycorrhizal treatment and biostimulant to assist the tree in taking up and metabolizing moisture and nutrients.
It is important to give a Redbud tree suffering from verticillium wilt a deep root watering at least twice or three times a week. The objective of a deep root watering is to ensure that the water penetrates deep into the soil, to a depth of at least 24 to 36 inches so that the entire root zone is hydrated. The easiest way to give a large tree a deep root watering is to place either a sprinkler or a soaker hose over the tree's drip line and let it run for about 2 hours, ensuring lots of water penetrates the soil. A deep root watering is much better than frequent shallow waterings which do not get moisture to the lower roots. During periods of extreme drought you may also want to consider spraying the soil around the tree's root zone with Hydretain Root Zone Moisture Manager. This is a unique and advanced product specifically designed to assist a tree in dealing with drought stress. It works like a natural magnet to hold water near the tree's root zone and keep the root zone hydrated during periods of drought stress.