Deciduous trees are plants that drop their leaves for a part of every year, usually during periods of dryness or cold weather. Their branches remain free of foliage until conditions improve. For the tree, this means that it can save energy by not working to keep the leaves green and healthy. Despite having to deal with the fallen leaves and bare trees for part of the year, many people find this type of tree quite attractive, and they are also appreciated for their usefulness, providing wood for things like fires, building, and sculpting.
Cause of Leaf Loss
Trees lose their leaves when they go dormant, which is a means of self-preservation. The majority of plants require sun, light, and water to survive, and when any one of these elements is lacking, the stress triggers hormonal changes. These changes prompt the tree to put more energy into simply surviving, so the it ends up losing leaves, which take a great deal of water and energy to maintain and grow.
Leaf loss usually happens in a fairly predictable pattern. The tilt of the Earth is a key player here, as it affects both temperature and amount of light the plant receives. When a section of the globe is angled more directly toward the sun and receives more light and heat, leaves tend to grow. If part of the globe is angled away from the sun and receives less light and heat, however, leaves tend to fall. People, therefore, link the loss of leaves with annual seasonal changes, particularly autumn, even though deciduous trees technically can lose leaves at any time of the year.
Small trees that lose their leaves during some part of the year can be just a few feet (a meter or less) tall. The largest varieties can reach many times this height in extended proper growing conditions. The tallest reported sugar maple, for example, reached 110 feet (33.53 meters), and most grow at least 40 feet (12.19 meters).
Many deciduous varieties, such as cherries, crabapples, magnolias, and dogwoods, flower when they are leafless or just beginning to grow new leaves. This aids the pollination process because the flowers are visible to insects and there are no leaves to block the wind from carrying the pollen.
Losing leaves also means that there is less surface area on which ice and snow can collect. The amount of weight on the plant isn’t as high as a result, which reduces the chances that branches will crack or break.
One of the spectacular things about these types of plants is the wide array of colors the leaves often display before being shed, which many people find quite appealing. Colors can range from bright yellow to crimson and many shades of orange in between. This incredible display often is intense enough to attract tourists or inspire art, such as photographs and paintings.
People plant these trees in part because their leaves tend to be broad enough to provide some level of protection from the elements. Broad foliage is desirable in warmer climates because it creates shade that keep people and animals cool. In fact, deciduous trees have been shown to reduce home cooling costs in the summer by up to 10%, according to the Morton Arboretum. In winter, the shedding of the leaves lets the sun reach homes easily and provide more heat.
Even though deciduous plants have an edge in terms of pollination, their leaves are attractive to a number of animals such as deer. Insects also eat the leaves. Losing too many leaves in a short time period can shock the tree or even kill it.
When conditions improve following leaf loss, deciduous trees have to expend an enormous amount of energy in order to grow them again. That means they tend to need soil that has more nutrients. People who want to plant these trees may need to fertilize the ground naturally or with commercial products.
Compared to evergreens, trees that drop their leaves also tend to have most foliage in their upper half, creating a canopy. This allows people and animals to move easily underneath, but it doesn’t provide as much privacy because the leaves don’t extend down very far. Most species really work only as simple borders and aren’t very effective as natural fences or hedges.
The colors that appear prior to the leaf shedding process can be breathtaking, but once the leaves fall on the ground, they provide a breeding environment for pests, including mosquitoes. The leaves often give off an overwhelming aroma as they decay, and they can stick to shoes and be carried indoors. People typically rake or mulch leaves to combat these issues, but this takes time and can be physically challenging to complete.
Deciduous trees often are part of general landscaping plans, although planters need to trim them periodically to keep them shaped, prevent limb loss, and keep them from interfering with nearby items such as power lines. Homeowners sometimes select them specifically because of the color of both the leaves and the blossoms, achieving a decorating effect out of doors. They are good for climbing, and the wood from many species can be used for building, sculpting, and as firewood.
Why Do Deciduous Trees Lose Their Leaves?
Trees shed their leaves to increase their chances of surviving the oncoming winter. Leaves require a lot of resources to grow and thrive that the plant simply cannot spare in the colder months of the year. In autumn, the tree reroutes its nutrient flow away from the leaves and down to the roots. This process continues as the tree enters a low-energy state known as dormancy.
Though trees are stationary beings, they are not as passive as they appear to be. These plants are highly responsive to meteorological and environmental changes throughout the seasons. Temperature and moisture fluctuations, both in the air and in the soil, heavily influence when a tree drops its leaves. Exposure to sunlight, frost, and winds can also affect the timing of this natural phenomenon.
External forces are not the only deciding factors at play. The individual species's genetic profile also determines when its leaves will fall. This is why certain types of deciduous trees shed their leaves sooner or later than others, even in identical environmental conditions.
Why Do Deciduous Trees Go Dormant?
The ultimate aim of dormancy is to keep the tree alive in harsher conditions. During dormancy, certain life-sustaining functions are prioritized over others. The growth rates slow dramatically, and without leaves, photosynthesis comes to a grinding halt. Dormant trees distribute some of the water stored within their cells into the empty spaces between cell walls to prevent a deep freeze. If a significant number of cells become frozen over, the tree will die.
When To Plant Deciduous Trees and Where
Spring is the optimal time to plant a deciduous tree, especially if it is being planted in an environment with hot, dry summers. Spring's mild temperature fluctuations encourage the newly planted tree to focus on developing its root system. Once the root network is extensive, the tree is more resistant to extreme temperature swings, such as summer heatwaves. Watering frequently during dryer periods stimulates root growth and prevents the roots from shriveling up.
Deciduous trees can also be planted in autumn, but this requires a lot more planning. Tree species that are acclimated to extreme seasonal changes are more likely to survive the winter in new soil than those that are used to temperate biomes. If you intend to purchase your tree from a garden center, select a sapling that has been grown in a container, such as a pot or a burlap sack. Avoid planting trees with exposed roots because they are more sensitive to colder temperatures. Once it is planted, you should water it often until the ground is hard.
Choosing the ideal location for planting is just as important as the timing. Trees should be planted in locations that are suitable for their environmental requirements. Sunlight exposure, soil moisture, and soil composition are important criteria that can be used to evaluate the eligibility of an intended location. New trees should also be planted at least 15 feet from any existing structures. Some species tend to have widespread roots and should be given even more space to grow.
Deciduous vs. Coniferous Trees
Over millions of years, most trees have evolved into two main categories: deciduous and coniferous. Deciduous trees enter a state of dormancy when natural conditions are not suitable for leaf growth, which results in the shedding of their leaves. This process usually occurs in autumn and is reversed in the spring. Deciduous trees also produce flowers to aid in reproduction during the spring and summer. When the flowers are fertilized by pollen, which is carried by pollinating insects, they create seeds. Examples of deciduous trees include oak, sycamore, and maple.
Coniferous trees, also known as conifers, use needles for photosynthesis instead of leaves. The needles are unaffected by seasonal variations and maintain their deep green hue throughout the year. Conifers reproduce without flowers and pollinators. They rely on the wind to carry their pollen to receptive female cones, which are generally referred to as pine cones. The pine cones protect the seeds until they mature, at which point the cones fall to the ground and scatter the seeds. Pine, spruce, and yew are coniferous trees.
Deciduous conifers are a smaller, tertiary category that encompasses only 20 tree species. They reproduce in the same manner as conifers and have needles instead of leaves, but they drop their needles in autumn like deciduous trees. Larch, dawn redwood, and bald cypress belong to this category. Both deciduous and regular conifers are also called evergreens.