Trees (Broadleaf)
In landscape applications the type of broadleaf tree planted should be determined by its location. Trees planted in islands of parking lots should not have shallow root systems as eventually, as the trees reach maximum size, the roots may break concrete and pavement and can also cause costly repairs to irrigation systems. Fast growing trees will increase maintenance costs by increasing pruning frequency. Landscape architects are usually familiar with which trees are best adapted to a particular geographic area.
Newly planted broadleaf trees need more irrigation than established trees, as the root systems are shallow. As trees grow the root systems grow deeper where the soil stays moist longer and less irrigation is necessary. A ring of mulch around newly planted trees will retain soil moisture and reduce the need for irrigation.
The proper staking of newly transplanted trees is very important. If not properly staked, trees of any type, but especially broadleaf species, will be blown over in high winds. This weakens the tree as new root growth is disrupted. Proper staking in northern climates is especially important as it may take several growing seasons for the root systems to establish. When dormant, the entire tree is dormant, roots included.
Trimming or pruning of a broadleaf tree is done primarily to shape the tree, to induce more growth, and to reduce the risk of personal injury or property damage. Many broadleaf trees have a natural round or oval crown. Some trimming may be required to maintain the crown. Dead wood and low hanging branches should be removed as soon as they are noticed. A dead branch will eventually fall so it is better to remove it before it has that chance. Low hanging branches over driveways or walkways should also be removed quickly. The cost of removal is less than a lawsuit due to personal injury or repair of a new car.
The crowns of broadleaf trees have a greater tendency to grow to a greater diameter than coniferous or palm trees. In any case though, tree foliage should never be allow to grow to the point where it touches a building, because high winds can cause branches to damage buildings. Insects can also use branches as entrance into the buildings. Pest control experts will always recommend trimming branches away from buildings.
Exotics trees
Exotics need to be mentioned. In warmer climates, certain trees have been introduced over the years that can be very invasive in landscaped areas. These exotics are usually native to tropical areas.
Tropical exotic invasive species can thrive in warmer climates, but are usually not a problem in colder climates as, being tropical, they will freeze before gaining a foothold. It is important to be able to recognize exotics, so they can be identified and removed before they take over. They are usually very fast growing.
In Florida one of the most invasive is the Brazilian Pepper. It is sometimes referred to as the Florida Holly due to the clusters of red berries it produces in the fall and winter. The sap smells of turpentine and can cause a rash on contact with skin. The seeds are eaten by birds and spread in the droppings. They are opportunistic and grow easily in hedgerows, beds, and along fence lines. If not identified and eradicated while small, they will grow into trees and overpower native vegetation. The best way to eliminate them is to hand pull them while they are small. If allowed to grow beyond that point, they must be dug out. Cutting them back will not work and will actually make them spread faster.
Herbicides are only effective when the seedlings are very small.
Almost every area in the United States has exotic plants. The Internet is the best source for identifying exotics in a particular area. Search Exotic Plants or Invasive Exotic Plants on any search engine. The agriculture departments of many states have websites that will help identify these types of plants.
Check back tomorrow for Part 3
Annotation: the term broadleaf is used to distinguish trees that are not coniferous and do not have needles and is often erroneously used as a synonym for deciduous. Coniferous trees are usually evergreen, but broadleaf species consist of both deciduous and evergreen types. Maple, oak, and beech are deciduous broadleaf trees. Holly is a broadleaf evergreen. In the tropics most broadleaf trees, such as the live oak, are evergreen.