Most deciduous species of trees are at risk if stressed by insect defoliation, weather, poor soil conditions, or other factors. One of the best things you can do is simply to keep your trees healthy with regular maintenance including proper irrigation and mulch, fertilization, and removal of dead wood. Healthy trees are better able to withstand an infestation. Once the damage is obvious, it’s probably too late to treat effectively for optimal protection. Be sure to inspect your trees for any signs of infestation in early spring. For more information call Tree Artisans at 719-822-6733.
MULCH APPLICATION AROUND TREES
Mulch keeps trees healthy by eliminating the competition between tree roots and turf as well as conserving soil moisture and moderating soil temperature. Ideally, mulch should be applied beneath the entire tree canopy, but smaller mulched areas are acceptable. Mulch depth shouldn’t exceed 4"; 2" is acceptable for shallow-rooted shrubs and perennials. Shrubs and perennials can be planted within the mulch areas, but solid masses of groundcover should be avoided for optimum tree growth. Too much mulch can lead to insect and disease infestations and other problems.
Defoliation – or loss of leaves – eliminates food production capability, which weakens the tree, reduces growth, and results in pale leaves and branch dieback. The effects can range from a slight reduction in vigor to complete tree death.
The forecast is grim when defoliation occurs early in the growing season when leaves reach full expansion. The tree has expended a considerable amount of energy on leaf development and food reserves haven’t had time to replenish. The tree is further weakened as it expends additional energy to refoliate. Trees that receive regular care – pruning, fertilization, mulching, and watering during dry periods – have a higher toleration for defoliation. If a tree is defoliated, watering during dry periods aids the refoliation process. Fertilization can also encourage refoliation and replenish nutrients.
YOUNG TREE CARE
The highest tree loss rates occur within the first three years after planting while the root system grows from the root ball into your soil. Many such losses are preventable with the right care. Watering trees at the right time and in the right way is the first step. Apply water to the original root ball and the surrounding soil once or twice per week during dry periods – depending on the weather and soil moisture levels.Proper mulch application conserves soil moisture and provides a better environment for roots to grow. Mulch should never be in contact with the trunk of the tree.
Pest management is also important because young trees can’t afford to lose leaves or branches to pests. Fertilization helps to establish healthy growth and is a cost-effective way to help turn small plants into larger ones.
MANAGING THE EFFECTS OF DAMAGING TREE INSECTS
Some common tree pests found in late spring and summer include borers, mites, scales, and beetles. They can cause wilting, canopy thinning, premature leaf drop, and branch dieback. Many of these insects feed on various types of deciduous and evergreen species.
Treatments – including the release of beneficial insects – can suppress the impact of damaging pests. Examples of natural predators to these pests include lady beetles, green lacewings, trichogramma wasps, and predaceous mites.
The first step to proper treatment is identification of the infestation type. After diagnosis, the best method of treatment can be determined and timed for maximum effectiveness.
CARE FOR MATURE TREES
As a tree ages, it becomes less able to adapt to major changes and is more susceptible to decline. The key to mature tree care is maintaining stable conditions, avoiding disturbances to the root system, and proper pruning to preserve structural integrity. Pruning of mature trees should be limited to dead branches. Foliage removal is recommended only when absolutely necessary. Soil management goals include: Simulate ideal conditions found in nature by mulching as far out to the drip-line as possible. Fertilize by prescription to correct nutrient deficiencies. Irrigate as needed to avoid drought stress
SHRUB PRUNING AND SHEARING
Shrubs are pruned to maintain size, remove old branches and stems that don’t flower, and eliminate dead and dying branches. However, pruning shouldn’t be confused with shearing.
Shearing is performed with manual or powered hedge shears to remove a portion of the new growth each year. Shearing alters the natural form of the plant to create a dense outer crown and a rigid formal appearance. Because only a portion of the new growth is removed, sheared plants become larger each year. It’s difficult to maintain the size, health, and appearance through frequent shearing, so it’s recommended only for hedges and formal shrub gardens. Late summer or fall shearing can lead to winter injury. Pruning removes current and previous seasons’ growth using hand pruners. Pruning is the preferred method for maintaining the size, shape, and health of shrubs. Through selective thinning, light and air can penetrate the interior crown to promote growth inside the plant.
Foliar diseases caused by fungi are common in the spring. As leaves appear, be sure to notice anything unusual in the foliage of your trees. Signs of problems include:
- Discolored or dead spots on leaves
- Unusual coating on the leaf surface
- Browning or yellowing on the outer margins of leaves or along leaf veins
- Bumps or pustules on leaves
- Loss of needles on conifers
Any species of tree can be impacted by foliar diseases. Infected trees can be unsightly, and tree health issues may arise when loss of leaves occurs. Effective management varies according to the underlying problem so trees with symptoms should be inspected by a certified arborist.