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.

April is the time to get routine watering started – and the Denver tree services can offer the best advice for when to water and get a good spring start on your landscaping.

Another important area to focus is on fruit trees and fire blight. Ornamental trees are awfully pretty when they bloom, but the fruit they yield isn’t fit to eat. Property owners who have buckthorn, mulberry, persimmon, and female gingko know that this unwanted fruit is unsightly, smelly, and messy. For those who own fruit trees for their sweet harvest, fire blight features in their nightmares. Regardless of whether your fruit-bearing tree is there for looks or for production, Denver tree experts recommend prevention over correction.

Fruit reduction treatment

Tree service companies offer fruit reduction sprays to reduce or eliminate undesirable fruit development, particularly useful in trees valued more for their ornamental properties than for food production. Hormone sprays are used on fruit trees to minimize fruit production. Be aware that some chemicals may not be legal for household use and others may be prohibited entirely. A single application may be insufficient and require a second treatment.

The wise homeowner considers the following variables before spraying:

• How much fruit the plant yields. If the tree tends to produce only a little fruit, hand removal might be the best option to eliminate unwanted fruit.
• How valuable the plant is. If the time, effort, and expense of maintaining the plant outweighs its value to the property owner, then consider removing it and, perhaps, replacing it with a lower maintenance tree or shrub.
• When the treatment is applied. The window of opportunity for foliar sprays can be narrow. American Arbor Care recommends application of fruit prevention sprays when the trees are 85 to 100 percent in bloom, but before the fruit sets. The Morton Arboretum suggests timing daytime application when temperatures are consistently between 65 and 95 degrees Fahrenheit.

Fire blight treatment

Cornell University stated that fire blight “is one of the most destructive diseases of apple and pear trees” and is prevalent during cool, wet springs. Whether your orchard has one tree or a thousand, here’s what to look for to determine if your fruit trees have been infected:

Shortly after blooming, blossoms appear water-soaked and gray-green, then quickly turn brown or black.

• After the petals fall, leaves and stems on young shoot tips turn brown or black and curl “like a shepherd’s crook or candy cane.”
• The diseased shoots seep “small droplets of sticky bacterial ooze” in warm and humid weather.
• “Dark sunken cankers” will form in older wood.
• Fruit will be undersized, darker than normal, and may be shriveled. It may also sport dark lesions and ooze more of that bacterial goo.

If left untreated, fire blight will not only ruin the harvest, but kill the entire tree. Plants other than apple and pear which are susceptible include quince, fire thorn, mountain ash, hawthorn, rose, and raspberry.

Controlling fire blight integrates practices that minimize the plant’s susceptibility, efforts reduce contagion, and applications that protect against infection. Horticultural experts recommend avoiding highly susceptible plant stock. In other words, choose hardier varieties. To reduce contagion, prune diseased branches and stems before the plant blooms, being careful to sterilize pruning shears after each cut. Destroy the pruned material; do not add the diseased branched the compost pile. Apply bactericide sprays when daytime temperatures reliably remain above 65 degrees Fahrenheit. Planet Natural also recommends early application of liquid copper at “silver tip and bud break” and repeating every three to five days as needed until the petals fall.

American Arbor Care offers comprehensive health management for trees and shrubs. Trust Denver’s tree pros to know what to do and when to keep your ornamental trees beautiful and your fruit trees productive. Call them at (303) 639-8584 to schedule a consultation.

The dreaded scourge of ash trees everywhere–the emerald ash borer–has spread to Colorado. Ash trees in Colorado already suffer from a native pest, the lilac ash borer. Both species cause destruction, but they’re not the same. With assistance from the Colorado State University Extension, Denver tree service companies explain the difference.
The lilac ash borer is native to North America and prefers already-stressed trees, white ash being favored over green ash. This pest is the larva form (caterpillar) of a moth which is a type of clearwing borer. An early-season pest, the lilac ash borer concentrates egg laying in the bark on the lower trunks of trees.

The emerald ash borer is an Asian invader. Despite bans on transportation of firewood and infested wood, the emerald ash borer has spread steadily across North America. Thus far, only the most western states remain unaffected. This aggressive borer is the larva of a type of beetle known as the “metallic wood borer” and favors green ash over white ash. The emerald ash borer lays eggs on the bark surface throughout the tree from late May through early July.
If the unstoppable invasion of the emerald ash borer weren’t distressing enough, research at Wright State University discovered that the emerald ash borer has expanded its diet. Apparently, the pest finds the white fringetree, a relative of ash, tasty and hospitable.

The white fringetree is native to the savannas and lowlands of the southeastern United States. It is a small, deciduous tree with fluffy, white flowers. It is also known as Graybeard or old man’s beard and most often used as an ornamental in landscaping. It resembles the Chinese fringetree, an import native to eastern Asia with dense clusters of small, white flowers.

Pest Damage

After hatching, lilac ash borer larvae tunnel through the bark and feed in the interior of the tree. Heavily infested trees will show deformities in affected trunks and branches. Emerald ash borer larva also tunnel through the bark to feed on the tree’s interior just under the bark. Their feeding paths girdle the tree which show outwardly as a progressive thinning of the tree canopy.

Pest Management

Treatment of lilac ash borer infestation involves the use of a spray insecticide applied to the trunk and lower branches of the affected tree. Tree pros time the application to either immediately before or at the same time the eggs begin to hatch.

Treatment of emerald ash borer infestation involves repeated applications of insecticides via sprays, trunk injections, and soil treatments.

Treatments used to control lilac ash borer infestations are not appropriate for emerald ash borer infestations.

Your Best Resource

American Arbor Care offers numerous insect treatments throughout the growing season to keep your trees and shrubs healthy. Trust the tree service 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.

The Lawn Institute invites you to celebrate April, which is National Lawn Care Month. As winter weather recedes and warm spring weather finally takes a firm hold, homeowners can get a bit of a reprieve on the usual lawn care worries. Denver landscaping services know that the rainy days and cool nights of April prohibit much outdoor work and reduce evaporation, so activate your sprinkler systems, and just add water when things get a little dry. 

For those homeowners who take pride in their manicured lawns, the following are some facts to rebut the arguments of lawn dissidents who rail against traditional landscaping:

1. Lawns prevent topsoil erosion by trapping more than 12 million tons of dirt and dust annually.
2. Sod (i.e., turfgrass) is a natural “air conditioner” and can be 22 degrees Fahrenheit cooler than the surrounding pavement.
3. Healthy turfgrass holds soil and filters rainwater, contributing to clean groundwater and preventing further soil erosion.
4. A 50 X 50 square foot lawn produces sufficient oxygen to keep a family of four breathing, while absorbing carbon dioxide, hydrogen fluoride, and perosyacetyle nitrate.
5. Simply viewing a soft green lawn or sitting on the grass relieves stress.

If you love a well-manicured lawn but detest the work that goes into keeping that lawn looking great, you may be considering hiring a lawn care service. April, being a low-maintenance lawn care month, is the perfect time to take action and find the contractor who’s right for your Denver landscaping needs.

Decide what you want. Do you merely want a lawn service to lift the burden of regular mowing, the full shebang of yard maintenance for grass, trees, shrubs, and flowerbeds, or something in between?

Does the service include unnecessary treatments? If the Denver landscaping service you’re considering routinely sprays for pests or problems that you haven’t experienced, then you may want to consider another company that provides the services your yard needs when it needs them.

Get referrals. Talk to friends and neighbors whose lawns you admire and envy. Surely some of them use landscaping services and will be glad to recommend those companies. Don’t forget to check with your local Better Business Bureau, too.

Request an inspection. A reputable company will inspect your lawn and offer a free estimate for service to bring it to tip-top shape. Any company that hasn’t seen your lawn cannot know what it may need. Be sure you understand exactly what services are included in the estimate.

Does the contractor offer a discount for prepaid accounts? Many Denver lawn service companies will offer a discount for prepayment of annual service contracts. This may be a great way to save money on a service contract that includes the services your yard needs.

Understand the guarantee. Some companies will guarantee results, others will refund money for unsatisfactory work.
Verify certification. Certification indicates that that the contractor has met rigorous, third-party standards of competence and makes the effort to stay current with industry updates and best practices. A certified professional has made this field a career, not just a job.

American Arbor Care offers comprehensive landscaping and lawn care services and maintains a staff of experienced, certified professionals. Call them at (303) 639-8584 to schedule a consultation and learn what can be done to make your lawn the envy of the neighborhood.

If your spruce trees and pine trees are looking stressed, check them for western pine or ips beetles. Horticulturalist Joe Julian at the Colorado State University Cooperative Extension writes that ips beetles favor damaged or recently transplanted trees, but in times of heavy infestation, they will attack healthy spruce and pine trees. Denver tree pros recommend that homeowners treat their valuable pine and spruce trees now to kill off beetles emerging for their spring flight.

Also called engraver beetles, these pests embed themselves in tree bark and gouge the wood beneath. They’re small, about ⅛ to ⅜ inch long, reddish-brown to black, with a depressed cavity and spines at the rear end of the body. Eleven species of ips beetle are native to Colorado and each species prefers a specific type of spruce or pine. They breed fast, with two to four generations occurring within a single season.
To verify whether a tree is infested the Colorado State University Extension and Colorado State Forest Service suggest looking for these signs:

1. The tree fades from the top down.
2. Reddish colored boring dust will gather in bark crevices and at the base of the trunk.
3. Peel back bark the size of a deck of cards and look for live insects.
4. Beneath the bark, look for “Y” or “H” shaped paths or galleries scored into the wood.
5. Woodpeckers feeding on the main stem or large branches.

Ips beetles emerge from winter hibernation when daytime temperatures consistently reach 50°F to 60°F and fly from March through November. They attack trees throughout the flight period, although most damage results from the spring flight.
Controlling ips beetle infestations requires vigorous tree growth. However, once a tree suffers infestation, there’s not much the homeowner can to do save the tree. Experts may recommend removing the infested tree.

Confine spraying to prevent infestations to large, valuable trees. (Western ips beetles prefer mature trees with at least a 4-inch diameter trunk (young, healthy trees being usually safe from infestations). Trees stressed by mistletoe, root cutting, wounded bark, soil compaction, drainage changes, drought, iron chlorosis, and infestation by other insects are particularly vulnerable to ips beetle infestation.

Carbaryl (trade name Sevin) and permethrin (trade names Astro, Dagnet) are the preferred chemical for preventative spraying and comes in a variety of formulations, with liquids often requiring dilution with water prior to application.

Protect Your Trees with Iron Treatments

In addition to preventative spraying, ease the stressors that make trees vulnerable to infestation. One stressor that may mimic other problems is iron chlorosis, caused by iron deficiency in high pH soils and evidenced by yellowing leaves. Iron chlorosis must be confirmed by soil testing. If confirmed, the problem can be treated. According to Utah State University Extension/Forestry, a “mixture of equal parts iron (ferrous) sulfate and elemental sulfur can produce lasting results and is relatively inexpensive.” Soil treatments may be less expensive than foliar sprays, but take action more gradually and result in a thorough treatment.

The certified arborists at your Denver tree service, American Arbor Care can assist homeowners with assessing and diagnosing the needs of their trees and perform deep root fertilization, insect treatment, and disease management. As licensed tree care professionals, our arborists are licensed in the application of pesticides. Call (303) 639-8584 to get your estimate started.

The weather as of late has been unpredictable to say the least. One moment, the sun is out casting warm rays on Denver, creating streams of water to flow through the streets, and the next moment – the sky is gray and heavy streams of snow fall to the ground. The blizzard was especially surprising, and created some major issues for home and business owners who hadn’t yet tended to their pruning needs. As your premier Denver tree service, we have a few things to point out that you should remember while we endure weather ranging across the board:

Storm Damage

Storm damage in Denver takes its toll on your plant life and trees in a big way. Mainly trees experience the worst of it with heavy snow and winds, the limbs tend to fall to the ground and can hinder growth. While it can be managed, it is best to allow your Denver tree service assess the damage and make their recommendations based on your specific situation. They will be able to enact a plan to care for your trees in the most effective way.

Proper Pruning

The best way to manage storm damage is actually taking preventative measures. Proper pruning procedures are integral throughout the year, especially before seasons we experience unpredictable and heavy weather patterns. Pruning your trees in winter and at the start of summer can prevent breakage of limbs and branches, creating health issues in the long run for your tree.

Early Spring Maintenance

In the first three to four weeks of spring, we see a lot of plant life beginning to wake back up. Bulb buds begin to emerge, color starts to show, and the green slowly starts to creep out into the sunshine. During this time, it is important to maintain a steady and regular watering schedule. If we have melting snow, it can take care of some of the hydration, but early watering is key for your fledgling plants to survive and grow strong in the upcoming months.

Preventative Measures for Insects

Remember the Emerald Ash Borer? It is getting close to that time again to keep the Emerald Ash Borers at bay and away from your trees. We will begin our injections for Emerald Ash Borers to keep your trees healthy and safe throughout the blooming season and into the summer. Scale insects are another major threat to your tree and shrub health. They are often undetected until you begin to notice your tree or shrub suffering or dying. The importance of catching the culprits before they are able to create issues cannot be understated. Allow the professionals to inspect and evaluate the overall health of your trees and shrubs to begin treatment as soon as possible if necessary.

Call our team of experts today to get started and assess your tree’s health. We can maintain a healthy landscape for you and your family and recommend the best plan of action for the future. If you have experienced storm damage at your home after the blizzard, get in contact with American Arbor Care. We can implement proper pruning procedures moving forward and get you back on track for this year’s beautiful spring season!

We’re well on our way to summer’s heat (even with snow on the ground) and it’s time get started on revitalizing those landscape showstoppers, specifically roses and ornamental grasses. April is the perfect month to get your rose bushes and climbing vines in shape for a magnificent display in your Denver landscape. For basic rose care, you’ll need protective gloves and a pair of sharp pruning shears.

1. Reduce mulch. With warmer weather, your rose’s roots are growing and no longer need the heavy insulation from winter’s cold. Remove some, but not all, of the mound of winter mulch around the base of your rose plants. Do this gradually over the course of a few weeks so your roses acclimate to the warming temperatures. Obviously if you have snow on the ground, make sure to wait until all has melted away. Gradual removal also protects the plants in the event of a late frost. Spread the old mulch around the soil; you’ll want a protective layer about two or three inches thick. Be sure not to cover the plant bases, as you want them exposed to sunlight to stimulate growth.
2. Remove dead or damaged material. Rake away or pick off any dead leaves or damaged stems littering the ground or still attached to the plant. Just to be on the safe side, don’t compost this material to feed back to your plants.
3. Water the roots. Check the soil about three inches deep. If it crumbles, then it’s dry and your roses need water. Water slowly and deeply to soak the roots. If the weather still threatens to freeze overnight, then be sure to water your plants during the warmest hours of the day.
4. Fertilize. Like any living organism, roses and grass need nourishment. Fertilize the plants, but not until the leaves unfold or you could risk jumpstarting fragile buds while frost is still a threat.
5. Spray. If you treated your rose last fall, then one more treatment before above-ground growth gets underway will help prevent a new infestation of fungus or other disease. Most applications require careful timing, so be sure to follow the instructions and keep a close eye on the weather.
6. Prune. After the last freeze and before the buds begin to swell, stimulate growth by lopping off dead or dying canes, canes that rub up against other canes, damaged canes, and canes thinner than a pencil. Once you’ve thinned out the plant, you can shorten it if it’s too tall. Cut plants back as much as 15 inches for a few, large flowers or cut them back as much as 24 inches for more, smaller-sized blooms.

If your landscape features the drama of ornamental grasses, spring maintenance is pretty simple. Just be careful to wear protective gloves, as many ornamental grasses have sharp edges.

Ornamental grasses love warm weather, so you’re not likely to see much, if any, growth in April. This is the ideal time to cut them back. Tie the grasses into a bundle and use sharp hedge shears or even a chainsaw to cut through the stems. Cut them down to just a few inches above-ground. With a bit of mulch, fertilizer, water, and warm sun, they’ll spring back to full glory by midsummer. Spring is also a great time to plant new stands of ornamental grasses.

American Arbor Care is a comprehensive Denver tree service company that also offers full landscape and lawn care services to help homeowners save time and effort, beautify their yards, and add value to their properties. If you’re not an avid gardener, but love a well designed and maintained landscape, call us at (303) 639-8584 to schedule a consultation to unleash the potential beauty of your yard. Don’t forget that our service discounts end on March 31st!

In the Denver area, it’s not uncommon for cool season lawns to look less than perfect after summer’s heat or winter’s cruel weather. Lawns at the end of both seasons are subject to damage, disease, and neglect. Fall is considered the optimum time for overseeding, but March offers the second best opportunity to improve Denver landscaping. 

Overseeding is also a simple way to thicken a thin and tired lawn and a lot less expensive and labor-intensive than replacing old sod with new.  Before overseeding your lawn, have your soil tested. Simply dig up some soil (about two or three cups is sufficient) from several areas of your lawn and put it in a plastic bag. Your local extension office can test the soil for you for a nominal fee.

Correct problems before overseeding: poor soil condition, improper drainage, soil compaction, insufficient water, poor fertility, poor air circulation, insufficient light, excessive thatch, grass varieties unsuitable for your area, and neglect. Many of these problems can be alleviated through lawn aeration.

Overseeding equipment comes in two basic types: slit-seeding and broadcast seeding. A slit-seeder has blades that cut through the thatch and open a shallow, narrow furrow in the soil into which the grass seed is directly deposited. A broadcast seeder sprays the seeds over the lawn. Landscaping pros generally recommend that broadcast seeding be performed in two passes at forty-five degree angles to make a diamond-shaped pattern. A split-seeder uses less seed; a broadcast seeder is faster and easier. If you haven’t the time or inclination to do this yourself, American Arbor Care can overseed your lawn and correct any pre-application problems. (Link: http://denver-treeservices.com/)

After overseeding the lawn, new grass seed will sprout in about seven to ten days under adequate conditions. It takes about eight weeks for an overseeded lawn to become fully established. Grass isn’t that fussy, but it does require some care. After overseeding:

• Water the lawn heavily to drive new grass seed into the soil where it can germinate.
• Until the grass seeds germinate, water frequently and lightly.
• After germination, water less frequently, but more heavily for deeper soil penetration to encourage stronger root growth.

Once the overseeded lawn is established, water it at the levels and frequency recommended for the species of grass.

Top Dressing & Pre-emergent Applications

Fertile soil is rich with microorganisms and organic matter. Colorado, in general, is not blessed with rich soil. Wind erosion and lack of rainfall are main culprits in the state’s poor soil quality. Urban and suburban traffic further compact clay-based soils, which impedes water penetration and root growth. Top dressing can have the following benefits:

• Enrich the soil and reduce the need for fertilizer.
• Expand the soil and reduce the damage of compaction.
• Increase the soil’s ability to retain water.
• Reduce thatch, so water, herbicides, and fertilizer can penetrate the soil.
• Prevent wildlife from gorging on the all-you-can-eat buffet you just offered by overseeding your lawn.

Pre-emergent herbicide applications can affect desirable plants. Therefore, it’s best not to apply these chemicals soon after overseeding, because the herbicide can kill the newly sprouting grass and negate your efforts to produce a thicker, healthier lawn. Apply the seed first and then wait at least six weeks (eight is better) so the new grass has a chance to develop a good root system before applying the pre-emergent herbicide. Although mulch and rock beds are a great way to keep weeds at bay, you may need to apply pre-emergents to them as well. The herbacide makes a 1/2″ barrier in the soil and prevents weeds from germinating, but doesn’t kill existing plants. Make sure to ask your Denver tree specialsts which pre-emergent is best for your plants, as some herbicides can damage perennials, including trees. 

How Much Do I Need?

Each application has its own guidelines for application. Don’t apply too much herbicide: it’s expensive and will not provide any additional benefit. Don’t apply too heavy a top dressing or you’ll smother the lawn. In fact, over-application may harm your lawn and other landscaping plants. Applying too little is ineffective and wastes effort, time, and product.

Landscaping Denver yards benefits from the knowledge and skills of professionals. American Arbor Care can determine what your soil needs, the correct ratio of grass seed to square footage and the correct amount of top dressings, pre-emergent fertilizers, and herbicides to apply. We will perform the applications at the right time so that your lawn has its best chance to become the envy of the neighborhood. Call (303) 639-8584 to schedule a consultation–and don’t forget to have your trees inspected, too! American Arbor Care is a professional tree service company offering the expertise and knowledge of certified arborists.  Take advantage of our special offer: for all of your 2016 spray and landscaping maintenance needs, prepay by March 31, 2016 and receive a 5% discount!