The end of May begins the summer vacation season with Memorial Day. Expect the imminent arrival of hot, sultry days with long hours of sunshine and, often, too little rain. The end of spring heralds parched lawns and flowerbeds. Better Homes & Gardens recommends that homeowners think about prevention rather than treatment to keep their lawns looking great, because the effects seen now are the result of damage incurred a month before. Denver landscaping services advise homeowners to get an advance start on their summer lawn care to keep their yards green and healthy throughout the season.

• Mowing. Don’t scalp your lawn. Aside from mowing regularly, set the mower blades high. Taller blades enable your lawn to absorb more sunlight, which is used to produce and send more nutrients to the roots and soil. Taller blades also provide shade to the roots, which helps them retain moisture in a hot, arid climate. If you have a mulching mower that chops up grass clippings, you’re ahead of the game when it comes to fertilization. If your mower doesn’t mulch and doesn’t have a bag attachment to collect clippings, then either distribute the clippings evenly across the lawn or rake them up and compost them. Heavy strips of clippings will smother the lawn beneath. And don’t forget to sharpen your mower blades.
• Fertilization. Experts at Lawn Care advise fertilizing the lawn in spring and late in fall for optimum effects. Organic fertilizers in the spring add valuable nutrients to the soil to kickstart growth. A thick, healthy lawn can better withstand the rigors of hot, dry weather and trampling feet as well as insects and diseases.
• Water. The absolute most important aspect of keeping a lawn healthy is proper watering. Your lawn requires one inch of water weekly–whether that comes from rain and/or irrigation. A quick test to see whether your lawn is receiving enough water is to poke a screwdriver into the ground. If it goes in easily, then your lawn is getting enough water. If not, then your lawn is too dry and you should add water. Be sure to water in the early morning hours so the soil can absorb the water before the heat of the day sets in.
• Seeding. Remember that it takes about six weeks for seeds to germinate and the seedlings to take root, so don’t be impatient when seeding those barren patches. Seed once, water regularly, and wait.
• Weeding. Dandelions, thistles, pigweed and other nuisance weeds should be uprooted and destroyed before they sink taproots deep into the soil and become impossible to eradicate. Your kids might miss blowing the seeds off dandelions, but your lawn will be healthier.

Keep it clean. Yard decorations, toys, fallen leaves, vehicles, and other debris left lying about will weaken the lawn, even if only from keeping the grass under constant shade. Debris, such as old leaves and garden waste, can create an imbalance of nutrients which then weaken the lawn and set it up for disease and insects. Disabled or “extra” vehicles parked on the lawn can compact soil and drip noxious fluids that poison the soil, contributing to bare spots and weakened sod.

American Arbor Care offers a full range of lawn care and fertilization services to keep your yard looking great throughout the year. Call the Denver landscaping experts at (303) 639-8584 to schedule a consultation and learn what can be done to make your lawn the envy of the neighborhood.

Now that it’s springtime in Denver, elm tree pests are starting to come out of their winter stages of life to feed. You may notice brown spots or circular holes starting to show up in your elm’s foliage. These are signs that your tree may be infested with a pest – and your next step should be calling your Denver tree service to help you mitigate the infestation.
Here are a couple common pests that are found on elm trees here in Denver:

Elm Leaf Beetles

A common pest of elm trees, the elm leaf beetle survives by feeding on leaves. In spring, females lay eggs, usually ranging from 5-25 on the underside of the leaves. When the eggs hatch, caterpillar like larvae emerge. Once they go through their three growth stages over the course of a couple weeks, they become adults and fly to the canopy of the elm to feed. You can identify the beetle by the olive green color and a black stripe on their body.
The damage that the elm leaf beetle causes is a telltale “shothole” (pin sized holes) pattern through the entirety of the leaf. Larvae also skeletonize the surface of the leaf which causes it to turn white or brown. When there is an abundance of these beetles, they can cause a lot of damage and can even defoliate an elm tree. This decreases summer shade which leaves the tree in danger of sun scorching as well as depletion of the overall aesthetic value of the tree.

Elm Weevils

Starting in May and early June, elm weevils start to chew from the underside of leaves and can cause them to turn brown and fall off. The holes left by adults are pin sized – and although the damage is mostly an aesthetic problem, it can lead to severe defoliation which can weaken the tree. This makes it more vulnerable to disease or other pests. To prevent these weevils from making a home in your elm, it helps to water and mulch properly. Learn more about a proper watering routine and how you can get a good spring start on your landscaping.

Elm Leafminers

The elm leafminer, a wasp like insect, emerges from overwintering in spring. One thing that makes these pests efficient and abundant is the females are capable of producing eggs without males. The larvae tunnel into the leaf which cause major damage to the leaf and can cause it to fall off. The leafminers create “mines” (hence the name), which appear as small white spots and can grow bigger into a “blotch mine.” Blotch mines are elongated tunnels through the veins of the leaf. This can be a problem for the aesthetic value of the tree and over time, can damage an elm’s delicate foliage.
If you suspect you have any of these elm tree pests, the first thing to do is identify them. Your Denver tree service can help do this and take the correct course of action.  Call American Arbor Care today at (303) 639-8584 to learn what our tree & shrub management services can do to make sure your elm stays beautiful and healthy for seasons to come. 

May is the month when homeowners begin spending quality time in their yards. It’s also the season for the emergence of aphids and mites. Both pests can inflict serious damage to trees and shrubs and infestations of both can be treated. Denver landscaping experts offer some advice.

Spider Mites

If you thought emerald and lilac ash borers were pestilence defined, then you missed out on the invasion of the spider mites. This nasty, little bug is most active in the cool spring and fall. It feeds on conifer needles, causing a bronze or rust colored discoloration to the needles and may result in leaf drop. Damage often times won’t show up until summer when it’s too late to save the tree.

Spider mites prefer feasting upon distressed trees, so your best defense is to keep your trees healthy and remove any trees that aren’t. Keeping trees healthy includes providing them with adequate water and mulching to protect against temperature extremes.

Several generations of spider mites can be produced in a single season. Overwintering eggs hatch in early spring and eat old growth. Females lay their eggs on the bark of small branches until the first hard frost.

To diagnose a spider mite infestation, look for:

• Stippling on leaves as they feed
• Bronze or rust coloration on conifers
• Fine webbing between joints and twigs (hence the term “spider” mite)

If you shake a branch over as sheet of white paper and bugs fall onto the paper, get them tested. Susceptible trees include Colorado spruce, Norway spruce, white spruce, white pine, arborvitae, cedar, Douglas fir, hemlock, juniper, and larch.

Treatment: Many professionals rely upon soil applied systemic insecticides to treat spider mite infestations. Such treatments may work in as little as three days, with ongoing effectiveness lasting up to 30 days. Foliar sprays applied just after bud break in the spring and again when temperatures cool in the fall have also been effective.

Aphids

There’s nothing uncommon about aphids. With over 400 species, these pests suck the sap from tender new growth. The galls that result aren’t pretty, but an aphid infestation won’t normally cause serious damage to established plants. Aphids aren’t picky; no plant is safe from their voracious hunger.

Honeydew, a sticky substance excreted by aphids, is proof positive your trees and shrubs have an infestation. It can coat sidewalks, vehicles, and other structures–a sticky mess. Aphids hatch in the spring from overwintering eggs. The young bugs migrate to their summer feeding grounds where they quickly begin hatching several more generations over the course of a season.

Other symptoms of aphid infestation includes curled, discolored leaves and a black fungus called sooty mold (which may grow on the honeydew). The presence of ants and bees attracted to the honeydew may also denote an aphid infestation.

Treatment: Professional arborists typically apply chemical soil drenches or soil injections for long-term control. These types of treatments, however, take up to sixty days to take effect. A second treatment option is a foliar spray, the effects of which may last up to two weeks.

American Arbor Care specializes in tree and shrub health. Trust your Denver tree service professionals to accurately determine the pest infestation and to know how to control it. Call us at (303) 639-8584 to schedule a consultation and learn what can be done to make your lawn the envy of the neighborhood.

Scale (i.e., sucking) and borer insects emerge in spring from overwintering eggs, and most species can reproduce several generations until they die off (or go dormant) in the fall. Some species don’t seem to do much damage, while others will kill a tree in a single season. The list of pests is extensive and includes: bronze birch borer, cottony maple scale, kermes scale, elm leaf beetle/weevil/miner, striped pine scale, San Jose scale, spruce bud scale, pine needle scale, juniper scale. Treatments to prevent infestations usually involve foliar sprays and soil injections. Your Denver tree service company can guide you further.

Which bug is it?

Scale Insects: The University of California Agriculture and Natural Resources provides a detailed description of this type of pest. Scale insects insert “strawlike mouthparts” into bark, fruit, or leaves, with some doing considerable damage to their hosts. Eggs hatch into tiny crawlers that begin feeding a day or two after emergence. They develop through two nymphal growth stages before maturing to adult form. Settled nymphs may never move from their chosen spot, while other may move very slowly.

Infestation will weaken a plant and slow its growth. The plant may appear water stressed with yellow leaves that may drop prematurely. Heavily infested branches may die with the brown, withered leaves giving the limb a scorched appearance. Some scale insects produce honeydew, a sticky substance that attracts sooty mold and ants.
In warm weather, scale insect populations can grow very quickly.

Borer Insects: Entomology, published by the University of Kentucky, discusses borer insects, which “are among the most destructive pests of ornamental trees and shrubs.” The larvae stage of some species of moths and beetles tunnel under the bark in living wood and feed on the connective tissue. Points of entry enable pathogen to enter the tree, compounding infestation with disease.
Heavy infestation causes girdling, branch dieback, and structural weakness. This type of insect prefers trees already stressed by soil compaction, drought, sun scald, or other damage.

Treatment

Preventative maintenance is better than treatment, as diagnosis of an infestation may come too late to save the tree or shrub.

Once you have assured that your plants are properly cared for and healthy, they can be sprayed with a horticultural oil or foliar spray. Horticultural oils kill scale insects on contact, but have little adverse toxicity to pollinators and other natural enemies. More than one application may be needed. Horticultural oils are most effective in the spring on deciduous plants and the insects are in the first nymphal stage. Foliar sprays offer more broad-spectrum pest management, but may also be toxic to pollinators. Foliar spray runoff can also contaminate surface water.

Systemic insecticides can also be used. These are found under the terms of soil injection or soil drench. The pesticide is absorbed by the roots and then spread throughout the organism. Because of the deep penetration of the chemical throughout the plant, it may be more effective than a spray. The University of California cautions that systemic treatment may lead to spider mite outbreaks. Trunk injection is discouraged, as tools may become infected and spread disease from plant to plant, and wounds caused by the tools offer unimpeded entrance to pathogens.

Replace, don’t treat, severely damaged plants. Professional tree removal services in Denver will safely cut down the plant, which must be burned or otherwise destroyed as quickly as possible to prevent any remaining pests from escaping to nearby trees.

Call the tree experts

American Arbor Care specializes in tree and shrub health. Trust your Denver tree service professionals to accurately determine the pest infestation and to know how to control it. Call us at (303) 639-8584 to schedule a consultation and learn what can be done to make your lawn the envy of the neighborhood.