Why evergreen trees

Deciduous trees notice this, and, to prepare themselves for the oncoming winter and lack of opportunities for photosynthesis, they begin to reduce their production of chlorophyll to zero.

Without chlorophyll, the leaves lose their green and turn red, yellow, or orange. While winter can affect the metabolism of coniferous trees i. Instead of leaves, evergreens have needles that have multiple growing seasons each year. This allows the tree to hold onto their needles longer and continue to provide them with chlorophyll and keep them green all year long.

These multiple growing seasons throughout the year also help evergreens grow in climates and environments in which normal leaf-bearing trees would struggle, such as at high altitudes and latitudes. Evergreens grow in a way that allows snow to fall off them during times of accumulation. So, why are evergreens — like conifers such as pines , firs, junipers and spruces — immune to seasonal leaf changes and shedding, while species of deciduous trees — like aspens, ash, birch, cherry, elm, oak, poplar and maple — aren't?

It mostly comes down to a little thing you might have learned about in biology class called photosynthesis. Both deciduous and evergreen trees use energy from the sun and water from the ground to turn carbon dioxide in the air into food. The difference is that shorter days brings less sun during the fall and winter and that translates into less energy. So deciduous trees bearing broad, flat leaves go dormant or into a hibernation mode and shed their leaves to help them conserve water and stay alive until spring arrives and new leaves grow from new buds.

Evergreens, meanwhile, boast needles that are actually tightly rolled leaves, and this shape helps the needles conserve water throughout the fall and winter. A waxy coating on the needles also helps keep water from evaporating. These rolled-up, waxy needles resist cold and stay moist, which keeps them green throughout the winter.

What kinds of evergreen tree species are growing in your state or neighborhood? Can you find some of their needles or pinecones Or do you have other kinds of trees in your part of the world?

Tell us about what you see and send a message to Dr. Universe wsu. Search for:. Videos Activities Podcasts. When you are planting a hedge, they only need to be5 to 6 feet apart.

Water your trees regularly and keep the soil moist at all times but not soggy. You can fertilize your trees if you choose, but they do not require fertilization. If you choose to fertilize, use a balanced tree and shrub fertilizer. However, it can affect other species of cypresses like Thujas, and Junipers. This causes browning of the needles on the lower part of the tree next to the stem.

The infection eventually spreads upward and outward until only the needles on the tips of the branches are green. You can recognize this disease by the green pustules on the surface of the needles.

This will spread mostly during the spring and summer by the wind. You can treat these trees by spraying them with a copper-based fungicide. Continue spraying the tree until new growth pushes out. Seiridium Canker: This canker is one of the most damaging diseases to Cypress Trees. The canker can form on the stem or the branches, causing them to die back. They appear as brown or purple patches on the bark with resin coming out of them.

Eventually the twigs and branches will turn bright red and then brown before dying. There are no chemicals that can be used to treat this at the time. You can avoid spreading the disease by keeping the tree from getting wounded and pruning off any infected branches or twigs. Also, sterilize your pruning tools in bleach prior to prevent rusting. Botryosphaeria Canker: Similar to the Seiridium Canker, this fungus can cause reddish brown twigs and branches.

These cankers will not harm the trunk but will kill off the branches. The Botryosphaeria will attack trees that are under a lot of stress. In order to prevent this disease from attacking your trees, it is best to maintain good health for your tree. Mulching, and providing a good amount of water to your trees during extreme heat and drought will help.

Spruces are pyramidal trees than can be known for their stylish cone-like form and whorled branches. The needles on these trees are attached to the branches in a spiral like formation. They require full to partial sun in order to thrive. Planting: Plant spruce trees 20 to 25 feet apart. Make sure that you water your trees regularly in order to maintain moist soil. These evergreens do not need much fertilizer just plenty of sunshine and water.

However, if you choose to fertilize these trees you can use a tablespoon of balanced tree fertilizer and sprinkle it on top of the ground around each tree.

Spruce Needle Rust: This infection can cause your needles to become discolored, while the bugs remain green and alive.

You will notice the needles will drop of the next year. This can eventually cause the whole tree to turn a tan-pinkish color. This infection is not treatable. Depending on how serious the infection, the tree may not survive.

If you use a magnifying glass you will notice mites, and eggs on the twigs. There will also be webs on the twigs. You can use a miticide to treat your tree. You can also treat your tree in June and July to prevent mites from getting on your trees in general.

Common Needle Cast: Older infected needles turn a tan color as a result of this fungus. Normally the tree naturally sheds most of its needles.

However, the infection causes them to fall off prematurely. When you take closer look at the needles, you will notice black fruiting bodies on the bottom of the needles. To prevent this, you can apply a single application of fungicide at the beginning of summer. These trees are known for their handsome cone-like shape and rich, reddish brown bark which often peels off in strips.

These large trees can reach heights of 35 to 45 feet. They also have needle-like leaves that form spirally scales on their branches.