The Lifecycle of Trees
Trees have various stages of life, just like humans. Each stage has its own requirements to fit the tree’s needs at that point in the life cycle. Knowing how to care for your trees depends on the stage of the tree’s life.
Caring for Seedlings
A newborn or seedling typically starts out life as a seed or acorn. Planted by man or nature in the right soil, at the right depth, with a little water and warmth, it will soon sprout into a bouncing baby tree. Seedlings tend to grow rather quickly if the conditions are right, but this is one of the most vulnerable parts of the tree’s life cycle. Droughts, lawn mowers, and animals are all natural enemies. Due to these hazards and many others, only a small percentage of newborn trees progress beyond the seedling stage. The care they need is mainly in the form of physical protection, along with the right amount of water and nutrients.
Trees grown in the nursery are often grafted onto the root system of a compatible tree. One reason this is done is because the particular variety does not propagate from a seed or cutting. Another reasons is because it is a way to get a genetic duplicate of the same tree. Grafting plant material does not have to be done at the root level. It can be done on stems or even along the trunk of an older tree. Trees grown in a nursery environment have a distinct advantage in survivability rates due to the expert physical care they receive.
The Next Life Stage: Saplings
Soon, the next stage of tree’s life will begin. The seedling will grow into a sapling. Saplings have started to take root, and this is the size where most nursery stock is brought into the landscape. The trunk diameter is about an inch or larger at chest height. Saplings are not as defenseless as seedlings, but they are still vulnerable to threats that include competition from larger trees, poor weather, and animal or human damage. Saplings are generally not able to reproduce. This is an important time to prune young trees to ensure proper branch spacing and scaffolding, strong trunk taper, and a single dominant trunk.
The Best Years: Young Maturity
The next stage in the life cycle of a tree is young maturity. Young maturity is the point where the tree reproduces and flowers, and the tree is in a vigorous growth stage. As the young tree comes of age, it offers shade, fruit production, screening, and noise reduction.
To care for young mature trees, they should still be pruned on a regular basis to ensure these benefits. This life stage may require additional pruning that might include cutting back from buildings, lights, and walkways. Additionally, weak, dying, diseased, and other problem branches should be removed. Trees may be in this stage for a few years or many decades, depending upon the species.
Caring for Trees in Older Maturity
When a tree enters an older maturity stage, it may still have many years of valuable life left in it. It may start to lose lower branches that are shaded out by the upper canopy. It is now quite large and has often become a prominent feature within the landscape, offering both beauty and shade. Regular pruning will help keep it healthy by removing dead and other problem branches.
The mature tree might be a candidate for lightning protection to reduce the risk of a catastrophic strike. Installing a lightning protection system can be expensive. There is a lot of labor involved and copper is expensive, so this option is usually reserved for particularly valuable specimens within the landscape.
As roots grow as far as two to three times the diameter of the canopy (or drip line) in mature trees, it is important to protect them from compaction and competition for water and nutrients. A two- to three-inch layer of wood-chip mulch out to the drip line will go a long way toward alleviating both of these problems. Additionally, mulch has the advantage of recycling nutrients back into the soil as the wood chips break down.
Eventually most trees will reach the point of decline. This may happen for some species after only a couple of decades, usually due to the trees’ inherent structural problems. Bradford pears, for instance, tend to outgrow themselves and may start to break apart at about twelve to fifteen years of age. Other fast-growing species, such as Leyland cypress, may simply grow too big for their structure to withstand the next heavy ice storm. But for other species, including the bristlecone pine or the giant sequoia, the start of decline may not happen for several millennia.
When decline does eventually begin, the tree may still hang on for a long time. Sometimes a top will blow out in a storm or other disaster, but the lower part of the tree still remains viable. These old, decrepit trees may remain for a generation or more, but eventually they will succumb to disease or physical damage and will die. But the story is not over just yet. As these trees decay and fall apart, they recycle nutrients back into the soil and become a source for new life.
To learn how to care for your trees at any life stage, contact Growing Earth for a free consultation.