When the leaves came out on my redbud tree this spring, half the tree had normal-sized leaves that sprouted at the normal time. The other half had smaller-sized leaves that came out at a slower pace. The 2 halves remained this way throughout the summer, although the half with the normal leaves is now heavy with seed pods. The tree shows no signs of disease. It is treated by a tree service 4 times from spring to fall for various things. The tree is several years old, has western exposure and is watered by the yard sprinkler system. I put a slow drip water hose at the base a few times in September. Some of the roots are at soil level but are covered with mulch. I haven’t had the soil tested to know its condition. How can I keep this tree healthy so that it comes back all normal next year?

The symptoms you have described lead me to believe that the problem lies in your redbud’s (Cercis canadensis) reduced ability to take up needed water and nutrients that sustain good growth. Trees or portions of trees can become deficient in moisture and nutrients for a variety of reasons. These include a lack of soil moisture, compacted soils, injured or diseased roots that reduce water uptake, and injured or diseased trunk and branches that restrict water movement. Your tree service has physical contact with your tree several times a year and should be aware and monitoring its unhealthy symptoms. Check with them to ensure they are taking steps to promote a healthy outcome. Ask them about their spray schedule for your tree and what their treatment objectives are. Being an active participant will enable you to maintain a healthy environment for your plants.

I planted a silver mound in mid-August. As of late September, it wasn’t very big (about 8 inches), but it is already “flopping” (i.e. parting in the middle). Why is this and what can I do to prevent it? The plant is in full sun.

It sounds like a case of too much of a good thing. Silver mound (Artemisia) tends to get leggy and flop in the humidity of our summers, especially if grown in good garden soil. Relocation to an area of sandy, lean (nutrient poor), and fast-draining soil in full sun should postpone the flopping next summer. However, silver mound can still separate by late summer if allowed to get too large. If this occurs, it can be sheared back for fresh growth.

Late this summer, the top vertical stem of our white pine turned brown and died. The balance of the tree remained healthy. In the fall, the brown began moving down the tree. This tree is about 7 years old and sits at the edge of our woods. It has eastern exposure with acidic soil. I am not sure if the sprinkler system hits it. When we first saw the top stem turning brown, we watered the tree several times with a Miracid. Earlier in the summer, we lost a white pine that started with these same symptoms. Is there anything we can do to save this tree?

Seeking the services of a certified arborist will be your best defense against losing your tree because it is exhibiting symptoms that can be caused by more than one problem. An insect, the white pine weevil, bores into the terminal shoot causing death of that branch. The weevil rarely kills the whole tree, but places it in a weakened state where the attack of other insects, diseases, or environmental problems can cause gradual death.

Eastern white pine (Pinus strobus) is a fast-growing tree. Unfortunately, as they mature, many develop problems. The symptoms reported are a general off-color, yellowing or browning of the needles, stunted growth, stunted needles, or total browning of the tree followed by death. The cause for the decline is most often due to environmental stresses rather than a particular pest. The stress opens the door to secondary attacks by diseases and insects, which then accelerate the decline of the tree. Stress is the primary problem because it weakens the tree’s natural resistance.

Location of a white pine tree is very important for proper health and vigor. White pines require well-drained, deep, fertile, acidic soil with a moderate amount of moisture. They do not tolerate poorly-drained soil, high pH, compacted soil, a thin topsoil layer, buried debris or drought. Any other conditions that restrict root growth are also detrimental to white pine trees. Root diseases and cankers are the most common fungal pathogens that attack the Eastern white pine. Root disease symptoms are characterized by overall poor growth, the tree becomes off-color, wilts and dies.

Insects often act as vectors (transporters of the pathogen) for diseases. They breed in the dead trees and stumps. Then the new generations move to the surrounding stressed trees, bringing the disease with them. Other attackers of stressed white pine include the pinewood nematode, which feeds on vascular tissue in the branches and trunks of all pines and some other conifers. An insect called the pine sawyer beetle acts as a vector for the nematode, introducing it to healthy trees. Damage from the pinewood nematode is seen as sudden wilting and death.

When Eastern white pine trees decline they should be removed quickly so they do not act as breeding places for insects that spread diseases to surrounding trees. Replace dead trees with other evergreens that can better tolerate the existing site conditions.