Pruning Your Early-Spring Bloomers – Recommendations from Your Denver Tree Specialists
Dev Team June 29, 2016

While Colorado weather tends to make its own rules in the summer, there are some key rules to follow if you want to keep your yard looking beautiful all season long. The Denver tree specialists at American Arbor Care have some recommendations on what to do, including details on pruning your early spring blooming shrubs.

What is pruning?

There are several different methods of pruning you might consider. Fine pruning removes smaller limbs simply for aesthetic purposes. Standard pruning takes care of the tree’s branch structure in general, improving the appearance as well as the structural integrity of the branches. Hazard pruning removes branches and limbs for safety purposes — such as heavy limbs dangling over your roof, or into the street. Crown reduction pruning is used primarily after storm damage.

Denver tree specialists give some major reasons for pruning your trees. General trimming is like giving a tree a haircut–it improves the appearance, as well as the health of the tree by removing dying or dead branches. When you do this, you also open up space for more sunlight to peek through, bringing benefit to your landscaping and even allowing more sun to filter inside your home at times.

What Needs to Get Pruned?

In late spring to early summer, it’s time to prune your early spring bloomers. Some examples of these plants, specifically ones found in Denver, are lilacs, forsythia, and magnolia trees. If you wait too long to prune, you run the risk of having fewer flowers in the following year.


The key to pruning lilacs, the iconic shrub with the purple flowers and a distinct smell, is to wait until after they’ve flowered. Your tree specialist will take a look at the plant and figure out what needs to be cut — but generally, they first remove any diseased parts, scaly growth, suckers, and flower heads.


Many people use the wrong technique when it comes to pruning their forsythia shrubs. Typically planted in an overcrowded space, it’s unwise to shear them back to reduce the size. Instead, prune the tallest, oldest canes which sit more closely to the ground. This will help avoid cutting off the newest growth, including the flowers waiting to bloom next year. Pruning too much from the top of these shrubs will result in spotty growth that may never fully  return.


Magnolia trees are another example of what should be pruned after the tree has finished blooming. In Colorado, these broad-leafed evergreen trees finish in late spring. Because of their height, for these trees it’s important to first prune any dead or dying limbs. However, use caution when pruning an older magnolia tree. Because older trees heal more slowly than younger ones, the potential for diseases grows when they’re pruned.

Instead of gambling with the right times and ways to prune your early spring blooming shrubs, call the best tree trimmers in Denver. At American Arbor Care, not only do we have experts on staff who can help you figure out the best schedule for pruning your trees and shrubs, but we will also be able to suggest different methods for taking care of the rest of your lawn as well. Call us today at (303) 639-8584 to schedule a consultation.

Denver Tree Pros Recommend Adjusting Your Sprinkler Settings for Summer
Dev Team June 24, 2016

The height of summer is approaching, and with it comes skyrocketing temperatures. 2016 is already on track to be the hottest year on record, as Denver’s multiple days of 90-to-100 degree temperatures can attest to. Once the city consistently clocks in above 85 degrees, it’s important to adjust your sprinkler clock settings to maximize zone watering times. Controlling when and how much you water will save your Denver landscaping, as well as help you conserve resources and energy. The goal is to keep your yard healthy while using as little water as efficiently as possible.

Watering Zones
Most modern irrigation systems use a controller to regulate the length of time and amount of water used. This controller is an automatic timer that responds to the watering schedule you input, so it’s important to pay attention to weather conditions and make frequent adjustments accordingly during each season. Sprinkler systems in Denver are divided around your yard into areas called “zones.” Each zone has groups of plants with watering needs that differ from the other zones. Specific types of irrigation systems and irrigation system heads service specific zones. One to two inches of water is the ideal amount, depending on the soil structure, although areas such as the lawn need more frequent watering than trees, shrubs, or groundcover plants. Know your zones and what each one needs.

Irrigation Scheduling
To establish and encourage a healthy lawn and garden, every area needs to be watered regularly and evenly according to its needs. Having and maintaining an accurate moisture level will keep you from over- or underwatering, which could waste water and harm plants. Determining how much water each zone needs can be a trial and error process; consulting with a landscaping professional can help you set up the proper irrigation system for your yard. As a general rule of thumb, watering early in the morning during the summer is preferred. This allows the moisture to penetrate the soil and get to the roots before the sun causes it to evaporate. Watering during the day is much less effective, as it merely gets the plants wet and doesn’t provide enough time for the roots to absorb the water. Set your sprinkler clocks for early morning watering, but not for dusk or the evening. Photosynthesis can’t occur if the water has already passed through the root system.

Choose Efficient Systems

Expert landscapers and irrigation installers will know which sprinkler systems work best for the zones in your yard. There are low flow systems (drip lines, micro sprays) and high flow systems (fixed spray, bubbler), each designed to maximize the proper use of water. If you start with the right tools and keep a close eye on your equipment settings, your yard should continue to flourish even through the dog days of summer.

At American Arbor Care, we offer professional landscape renovation and irrigation services, as well as overall lawn care and tree and shrub health. Our experts can help you establish and maintain a healthy yard you can be proud of. Give us a call at 303-639-8584 to schedule an appointment and get started on your next project.

4 Threats to Your Lawn’s Health This Summer in Denver
Dev Team June 16, 2016

This is the season when your yard is at its greenest and most flourishing. Taking careful steps now for the treatment and protection against weeds and pests for your landscaping in Denver will ensure that your lawn looks lush throughout the rest of summer. The scorching heat of July makes some treatments, such as fertilization, unavailable, so it’s best to act in the next two or three weeks.

Broadleaf Control

Different in appearance and biology than normal turf grasses, broadleaf weeds are easy to identify and control without causing damage to surrounding vegetation. After your spring pre-emergent application of broadleaf weed control, to prevent seed germination, it’s time for the first of three rounds of balanced fertilization applications. Also, post-emergent spot spray treatment of lawn weeds that had already sprouted will continue.

Japanese Beetles

Keep an eye out for grub activity in your lawn at this time of year, particularly Japanese beetles. They are an invasive species with no effective natural enemies and voracious appetites for hundreds of different plant species. Metallic green with copper-colored wings, these insects emerge from the ground and begin feeding on surrounding plant life in late June or early July. Before that time, females will burrow several inches into the ground after mating to lay their eggs. They are attracted to damp, grassy areas with loose soil, so irrigated turf lawns are in danger of infestation. The grubs spend ten months developing and feed on the roots of turf grass, which causes the grass to lose its ability to absorb water. The result in the summer months is unsightly dead patches of lawn. These beetles can be controlled by properly-timed soil applications by lawncare professionals during the grub stage; the earlier any damage is noticed, the faster their destruction can be prevented.

Ascochyta Leaf Blight

Another potential lawn problem during this season is a plant disease called ascochyta leaf blight. It causes large swaths of turf to brown and die, and may appear as drought-stricken conditions at first. Ascochyta infests lawns quickly, however, and causes damage faster than drought. Grass that has been wet and then subjected to extreme heat is most at risk of infection, especially after a yard mowing. There are no necessary disease treatments for ascochyta; the best course of action is to over-fertilize the lawn, encouraging the turf to outgrow the blight, and to avoid mowing during wet weather to prevent its spread. Your expert local landscapers can help you select and apportion the correct type and amount of fertilizer for your turfgrass.

Necrotic Ring Spot

fungal disease that targets the roots of turf grass, necrotic ring spot thrives all across the country and is easily confused with other patch diseases. Circular areas of dead grass can begin to appear two to three years after a lawn is put in, though the symptoms intensify in the hottest months of the year, July and August. NRS can be eradicated with professional fungicide application and by taking good care of your turf by using properly prepared soil, overseeding infected patches, and not over watering.

American Arbor Care is your total Denver lawn care and fertilization specialists, offering all the services you need to protect and maintain the health and beauty of your landscape. We’re happy to answer any questions you may have about your lawn! Please call us at 303-639-8584.

Denver Tree Service Says Timing is Everything for Treating Pest Infestations
Dev Team June 9, 2016

As spring eases into summer, tree insects such as scales and borers begin to rear their ugly heads. Certain trees are susceptible to certain insects, and now is the time for specialized treatments to protect them from pest infestations. On the radar for the coming months for Denver tree pros are scales, borers, aphids, and mites.

Scales are some of the hardiest and most insidious pests in Colorado, causing branch dieback and even death in the infested tree through the long-term removal of the tree’s sap. The European elm scale, Oystershell scale, Striped pine scale, Juniper scale, and other scales are tiny, armored insects that secrete a waxy material from the pores on their back. This coating not only protects them from the hazards of Colorado weather, but also insulates them from some sprays used to contain them.

Aphids and mites, as well as scales, are sucking insects that cannot digest the sugars in plant sap. They produce a liquid called “honeydew” that drips onto the lower branches of whichever plant they have taken over; these shiny, sticky leaves are clear sign of infestation. Aphids and mites prefer tender, green buds and can be found on any new growth on your plants. Keep an eye out for these signs, as early detection and the development of a treatment plan with professionals is best for preserving your woody plants.

Emerald ash borers tend to do the most damage to ash trees in their larval stage, between August and October. These borers can infest ash trees for years before visible signs of decline appear. Infestation symptoms include sparse leaves or branches toward the top of the tree, along with vertical splits in the bark and damage to the leaves from feeding. Honey locust borers and oak borers are also active during this season, after hatching from eggs laid underneath the bark of honey locust and oak trees.

It’s vital that trunk treatments, either injections or sprays, are applied at the proper time for effective treatment against these pests. Scale eggs hatch in June and July, where the nymphs (or “crawlers”) then reside on the undersides of tree leaves until late summer. Borers need to be sprayed when they are newly hatched and emerging from the bark. Trunk injections every other year is recommended for keeping borers at bay.

Trunk injections are a treatment that uses a special injection tool to place and seal insect control directly into the tree, allowing the tree to distribute a minimal amount of pesticide from root to leaf tip. Trunk sprays are applied only to the bark of the trunk and lower branches; however, foliage doesn’t need to be treated. Both methods are quick and effective, with low environmental impact.

If you think your trees may need treatment, contact American Arbor Care, your Denver tree, shrub, and lawn specialists, dedicated to tree and shrub health management. Call (303) 639-8584 for your pest assessment, evaluation, and resolution needs.

Denver Tree Pros Recommend Borer Treatments Now
Dev Team June 1, 2016

’Tis the season for specialty borer applications to rid your trees and shrubs of honey locust borers, black locust borers, and viburnum borers. Like all borer species, these pests lay their eggs in the bark and the larvae which hatch then burrow beneath the bark to feed. Heavy infestations will kill a tree. Unfortunately, infestations are all too often detected too late to save the tree. When it comes to borers–not bores, that’s entirely different–Denver tree service companies advocate prevention over treatment.

The Morton Arboretum and U.S. Department of Agriculture Forest Service describe honey locust and black locust borers, which are similar.

Honey locust borers attack small and medium sized honey locust trees and branches, preferring diameters exceeding two inches thick. They prefer stressed trees to healthy plants. Adult honey locust borers emerge in June and feed on the foliage. Females lay eggs covered with a frothy substance that hardens. When the eggs hatch, the larvae burrow beneath the bark to feed. Honey locust borer infestation causes gradual decline of the tree and dieback of twigs and branches in the crown.

Black locust borers don’t eat honey locust trees, just black locusts and its cultivars. The larvae tunnel into the wood and weaken the tree’s structure, making it susceptible to breakage in strong winds. Adult black locust borers are easy to spot: about three-quarters of an inch long with reddish legs, black antennae, and bright yellow bands circling a black body. Adults often feed on goldenrod in the fall. Egg laying occurs in late summer through mid-autumn. Larvae emerge in spring and early summer. This native insect has a range that spans the Allegheny Mountains to Georgia to the Ozark Mountains.

Viburnum borersfeed on the lower parts of viburnum trunks, branches, and roots. Adults are day-flying moths that look like wasps with one-half inch long, bluish-black bodies with yellow markings and clear wings. Larvae are pinkish white caterpillars with reddish brown heads. Like most borer species, these prefer already stressed plants and aren’t fussy about which variety of viburnum they eat. Only arrow-wood viburnum is reported to be resistant.

Treatment is applied either as a spray or soil drench. Spray insecticides should contain permethrin or carbaryl to be effective and should be applied directly to the bark of the plant from the soil line upward. Preventive sprays should be timed just prior to egg laying for best results. Because timing spray applications is important, pheromone traps can be used to capture adult males to confirm insect activity.

As with all chemical applications, check to see whether certification or licensing is required before heading out to the local garden center to purchase a gallon or six. Because timing of the application is just as crucial as coverage, application of preventive sprays is best left to the experts to tree service company experts.

Should you discover too late that trees on your property have succumbed to borer infestations, the trees will have to be removed. Especially with locust trees and their long, sharp thorns, it’s best to hire a professional tree removal service to safely cut down the tree and remove the infested wood. Infested wood should not be composted.

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 and when to control it. Also experts in tree removal, our team can cut down infested and diseased trees safely and dispose of the damaged wood. Call them at (303) 639-8584 to schedule a consultation to protect your valuable trees.

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