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LSMP Tree Care March 200405-11-06 | News



Three on the Tree
Some Important Aspects of Tree Care

by Sean Stowell, regional editor








As a landscape superintendent/landscape maintenance professional, you know the importance of caring for the trees within your facility. In this inaugural installment of LSMP we will take a look at insects that can hurt and help your trees; we?EUR??,,????'???ll find out from Valley Crest Tree Company the best way to prepare the soil for a soon-to-be planted tree; and we?EUR??,,????'???ll check out the importance of proper fertilization for trees.

Insects?EUR??,,????'??+The Good, Bad, and Ugly

While there are insects that can do definite harm to trees there are also insects that are beneficial. The destructive critters interfere with sap flow and retard plant growth, but the beneficial insects can help with pollination and kill species harmful to trees.

It may be tempting to kill every bug you see, but you might be taking away nature?EUR??,,????'???s benefit to the tree. It?EUR??,,????'???s important to identify the good, the bad, and even the ugly insects when it comes to proper tree care.

?EUR??,,????'??The first thing to look for is the type of damage, and then look for the mouth parts of the bug,?EUR??,,????'?? Susan Sims of Sims Tree Health Specialists in Pedley, Calif., told LSMP. ?EUR??,,????'??Also look for quantity as pests are usually in large quantities and predators are loners or in small quantities.?EUR??,,????'??

The Big Three

Basically, insects can be divided into three categories according to how they feed: chewing, sucking, and boring. According to the International Society of Arboriculture, insects from each group have characteristic patterns of damage that will help you determine the culprit and the proper treatment. If there are any questions, always consult a tree care expert.

Chewing Insects:













These bugs eat plant tissue such as leaves, flowers, buds and twigs. Indications of damage by these insects are often seen by uneven or broken margins on the leaves, skeletonization of the leaves, and leaf mining. Chewing insects can be beetle adults or larvae, moth larvae (caterpillars), and many other groups of insects.Caterpillar damage on leaves is unsightly, but, unless plants are small when they are attacked, there is often little long term harm. Trees usually recover quickly and produce new growth. Even a severe caterpillar outbreak may be forgotten by mid-summer after the caterpillars have finished feeding and the trees have put out new leaves.

Sucking Insect













Suckers insert their beak, or their proboscis, into the tissues of leaves, twigs, branches, flowers, or fruit and then feed on the plant?EUR??,,????'???s juices. Some examples of sucking insects are aphids, mealy bugs, thrips, and leafhoppers. Damage caused by these pests is often indicated by discoloration, drooping, wilting, leaf spots (stippling), honeydew, or general lack of vigor in the affected plant. The damage done by aphids is due to a number of causes, including loss of sap, clogging of leaf surfaces with honeydew, and growth of molds and fungi on the honeydew. Leaf curl, a common symptom of aphid infestation, occurs when a colony attacks the underside of a leaf, causing its desiccation.

Boring Insects

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All pests in this category spend time feeding somewhere beneath the bark of a tree as larvae. Some borers kill twigs and leaders when adults feed or when eggs hatch into larvae that bore into the stem and develop into adults. Other borers, such as bark beetles, mate at or near the bark surface, and adults lay eggs in tunnels beneath the bark.

Bark Beetle Damage–One of the quickest methods of detecting and identifying bark beetle attacks is to note the point of attack and the type of pitch tubes created. Pitch tubes are masses of congealed resin that ooze out of the tree around the entrance hole of a bark beetle.

The black turpentine beetle usually attacks the lower part of a tree from ground level up to 8 or 10 feet. The pitch tubes are an inch or more in diameter and often appear purplish.

The Good Guys

You?EUR??,,????'???ve learned a little bit about the harmful insects, now let?EUR??,,????'???s take a look at some that may seem harmful, but in reality can help you and your trees out.

?EUR??,,????'??These bugs are faster and designed with predation in mind,?EUR??,,????'?? Sims said. ?EUR??,,????'??They often have big eyes and are built for camouflage or stealth.?EUR??,,????'??

Caterpillar Hunters













Hyposoter wasps are important parasites of many caterpillars, including corn earwom, lopers, and armyworms. The adult wasp lays its egg in the caterpillar. After hatching, the larva develops within the caterpillar, killing it before emerging.

Pentatomid bugs feed on a variety of prey but they have long been recognized as a predator of leafroller larvae, including lightbrown apple moth. It has usually been observed feeding on late stage caterpillars, but it probably also attacks younger larvae. The levels of morality attributable to this predator are unknown.

Aphid Hunters













The aphid midge can control more than 60 species of aphids. Adults are long-legged with prominent antennae and are active at night. Both the larvae and the eggs are orange. After the adult females lay eggs among aphids, the eggs hatch in two-three days and the larvae begin to feed on.

The Green Lacewing larvae of this bug is efficient against aphids. Later stages of this larvae will eat up to 50 aphids-per-day. Each larvae will eat a total of about 600 aphids in its two-three week larval stage.

Boring Beetle Hunters













Roptrocerus xlophagorum–The female enters the bark beetle maternal gallery for oviposition on bark beetle larvae.

Tomicobia seitneri–The female attacks the adult bark beetle and bores its ovipositor into the prothorax, rarely into the lateral sides of the abdomen or through the elytra. Parizitized beetles die after four weeks.

These are just some of the more common insects you?EUR??,,????'???ll run into out in the landscape, there are many more, and if you have question about something you come across, be sure to check with a certified arborist, or bug expert to make sure there is a balance between the good and the bad.

?EUR??,,????'??Basically, it?EUR??,,????'???s a whole educational thing to learn about insects,?EUR??,,????'?? Sims said. ?EUR??,,????'??Instead of spraying and killing everything, it is important to treat on an as-needed basis.?EUR??,,????'??

Now that you understand a little more about harmful and helpful insects, let?EUR??,,????'???s find out what it takes to successfully plant a tree and keep it healthy.

Planting Preparation

Planting a tree is a fairly simple procedure. Keeping it healthy in the early stages is the real challenge.

As a tree care professional you understand the importance of proper planting in a tree?EUR??,,????'???s success. There?EUR??,,????'???s the width of the hole, the height of the root ball, and what to use as backfill, that makes this process more than just placing a tree in a dug up piece of earth.






1. For specimen tree planting, dig the hole one to three times the root ball width, but not any deeper than the root ball depth.


The top of the tree?EUR??,,????'???s root ball should be level with or slightly above the surrounding soil. This limits the amount of settling that takes place after planting. Then the landscaper should crush the soil dug out from the hole and use this as backfill. Soil can be added around the tree until the hole is about half full, then the soil should be made firm to eliminate air pockets. The hole can then be filled all the way and the soil firmed up again.

?EUR??,,????'??A tree should be planted at grade or slightly higher,?EUR??,,????'?? said Robert L. Crudup, Jr., president and chief operating officer of Valley Crest Tree Company. ?EUR??,,????'??The pit should be deep and wide enough to get the tree in the hole and it should be backfilled with native soil.?EUR??,,????'??






2. It is important to stake or guy a tree after it has been planted. The nursery stake should be removed as it is only designed for temporary use.


Crudup advises that the hole should be dug about one-and-one-half times as wide as the root ball and only as deep. He also said that the edges of the hole should be scarified, creating a rough surface for the roots to penetrate.

?EUR??,,????'??Drainage is especially important in soils that don?EUR??,,????'???t drain well like compacted soils found on commercial construction projects or clay soils.?EUR??,,????'??–Robert L. Crudup, Jr.

Drainage, and the Right Amount of Water

Possibly the most important factor in the success of a newly planted tree is proper drainage. Good drainage is essential, so the planting pit should be checked before setting the plant. Fill the pit with water. If the water drains out within six to eight hours, there should be no problems. If on the other hand, water is still standing, artificial drainage should be installed.

?EUR??,,????'??Drainage is especially important in soils that don?EUR??,,????'???t drain well like compacted soils found on commercial construction projects or clay soils,?EUR??,,????'?? Crudup said. ?EUR??,,????'??Clay soils hold water and do not drain well.?EUR??,,????'??

Trees more often than not fail upon planting for two reasons?EUR??,,????'??+too much water or too little water and this is where drainage plays a key role.






3. Planting a palm tree requires backfill of 100 percent washed plaster sand. The palm trunk should also be vertical.


?EUR??,,????'??The key is for the root ball to get wet,?EUR??,,????'?? Crudup said. ?EUR??,,????'??Often times what happens is the water gets to the pit and the backfill takes in water but it doesn?EUR??,,????'???t get to the ball itself. The ball dries from the core to the edges and it is hard to get the ball wet again.?EUR??,,????'??

Once the tree is planted is should be staked or guyed, depending on the situation. It is important to remember that the nursery stake should be removed, as they are not designed for long-term use.

So now the trees are planted and the good insects are doing beneficial things and the bad ones are gone, it?EUR??,,????'???s time to find out how to keep them healthy year-round.

Fertilizing

Every good landscape has trees at its core. A well taken care of tree more than pays for itself in the long run. Proper fertilization is especially important to landscape plants in urban and suburban environments. According to the Virginia Polytechnic Institute and state University Cooperative Extension, modern building methods creates adverse growing conditions for plants. Good topsoil is completely removed and not replaced, and heavy machinery scrapes and compacts fertile soil, reducing its aeration and drainage.






4. There are many different planting and staking details used throughout the industry. While there are some site specific situations that require specialized detail, those shown here represent the more common methods.


Trees are autotrophs, which means they use nutrients to feed themselves by making sugar in the leaves that can be used right away, or stored as starch for future needs. While most soils have enough nutrients for trees it may be a good idea to get a soil analysis done before you fertilize. According to the St. Lawrence Community Forestry Program, trees adjust their growth and development rates to the level of nutrients, and will usually make out all right as long as the roots can continue to grow.

Proper Nutrients

Be sure to look for yellow leaves, reduced leaf size and retention, premature fall coloration and leaf drop and overall reduced plant growth and vigor. To help combat this start a fertilization schedule using slow-release fertilizers. They work best when applied in early fall or early spring. The roots will use the fertilizer in the fall and by the roots and shoots in the spring. If you work in the northeast standard fertilizers should be applied in late May or the early part of June.

It is also important to apply the correct amount of fertilizer. It is recommended to apply fertilizer over the entire root zone of a plant. To determine a plant?EUR??,,????'???s root zone, you must know the radius of the roots. The root radius is at least twice the radius of a plant?EUR??,,????'???s crown.

Here?EUR??,,????'???s an easy way to figure this out–if a tree?EUR??,,????'???s branches spread 15 feet from the trunk, then the roots spread 30 feet. The Virginia Cooperative Extension gives the following formula for finding the total square feet:

3.14×30 (root radius) x 30 (root radius)= 2,826 sq. ft.

Once this is figured, you can estimate the amount of fertilizer that?EUR??,,????'???s needed. It is advisable to use about two pounds of fertilizer per thousand square feet. Be sure to spread the material over the entire root zone. Also, dig holes throughout the root zone and fill them with fertilizer. It doesn?EUR??,,????'???t work because most feeder roots are in the upper layer of the soil.

So now you have an understanding of three important aspects of tree care. Good luck and remember to make sure the root ball gets wet, use the right amount of fertilizer, and keep in mind those aphid midges are there to help your trees.


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