Author: Burkholder PHC

Roses are a popular plant choice for homeowners, representing beauty and elegance, gracing gardens and landscapes with vibrant colors and rich fragrances. However, these delicate flowers are also susceptible to various types of disease and pests that can compromise their health and appearance. We have treated rose plants at multiple residences this season, and below we discuss some of the common plant health care issues for roses, focusing on disease prevention and treatment methods to help you keep your roses thriving and disease-free.

Common rose diseases in Pennsylvania include powdery mildew, Botrytis blight, Rose Mosaic virus, Crown Gall, and stem canker. Some of these diseases are fungal infections, while others are viral.

Powdery mildew is one of the most common foliar diseases of roses. The white, powdery fungal growth can be very disfiguring, with repeated heavy infection reducing plant vigor.

The powdery mildew fungus that affects roses is Podosphaera pannosa var. rosae, formerly known as Sphaerotheca pannosa.
Powdery mildew usually appears in spring or autumn when conditions are warm and humid, though plants can be affected at other times of year if conditions are right.

This a Rose bush we treated on a property for two common problems, including powdery mildew, that are relatively easy to identify. Powdery mildew is the cause of white and light grey spots on the leaves. The holes are caused by slug sawfly larva feeding on the leaves. Both will be treated and this rose will fully recover.

Rose rosette disease affects multiflora rose and ornamental Rosa genus plants., is caused by a virus (Emaravirus sp.) that is spread by a very small, eriophyid mite (Phyllocoptes fructiphylus). The mite feeds on the underside of leaves and injects saliva into the leaf tissue. The virus is then transmitted to new leaves when the mites move to new plants. They are wingless, but they can be carried on the wind or on clothing to new plants.

The symptoms of rose rosette appear as raised brown spots on new growth and on flowers. As the disease progresses, it causes deformation in the leaves and stems so that they resemble witches’ brooms.

Botrytis blight is a fungal disease that is quite common in roses. Most common in cool, damp weather, the fungus infects the plant, causing gray spots on the leaves and petals. The fungus can also move to the cane, or stem of the rose plants.

Rose mosaic virus is a viral disease that causes yellowing and distortion of leaves. Aphids and thrips can transmit it. An important distinction between rose rosette and rose mosaic is that the rose rosette virus will kill the infected rose plants. Rose mosaic virus disease may cause symptoms such as slow growth, reduced flowers and increased susceptibility to frost for the entire life of the plant.

Rose crown gall is a bacterial disease that causes tumor-like growths on the stems and roots of roses. Often considered a minor problem, it can cause considerable aesthetic damage to plants if left untreated.

Crown gall is caused by the bacterium Agrobacterium tumefaciens (AT) and is spread by infected plant material. The pathogen enters through wounds in the plant tissue, which may be caused by pruning, transplanting or other physical damage. Once inside, AT causes abnormal cell proliferation. This results in warty growths on the stem or root called galls.
Rose crown gall symptoms include the following:

• decreased blossoms
• formation of large, irregular swellings at ground level
• brown discoloration of affected stems

The disease can be spread by pruning equipment, or by galls breaking down in the soil. In the latter case, the pathogen can survive up to 3 years.

Cankers are caused by a variety of fungi. These diseases cause reddish brown spots on canes (stems) that become covered with tiny black dots. Cankers can eventually kill the cane, and can be spread through pruning equipment.

To prevent these diseases and other plant health care issues for roses, good cultural methods such as proper watering, pruning, fertilization, and soil care are vital. Additionally, organic or chemical control methods, such as fungicides and horticultural oils, can protect your roses from diseases.

Proper air circulation is crucial for maintaining the health of your roses. Good air circulation helps prevent the growth of fungal diseases by reducing humidity around the plants. To achieve this, roses need to be spaced adequately, pruned regularly, and any weeds or debris that may obstruct airflow need to be removed. Research has shown that proper air circulation can significantly reduce the incidence of diseases like powdery mildew in roses.

Some rose varieties are more resistant to certain types of disease and pests than others. Choosing resistant varieties can reduce the need for chemical treatments and make maintaining plant health more manageable. Recommended disease-resistant rose varieties include ‘Knock Out,’ ‘Carefree Beauty,’ and ‘New Dawn,’ among others.

In early spring, roses need to be pruned to remove dead or diseased wood, fertilized with a slow-release fertilizer, and a dormant oil should be applied to control pests. Proper pruning is essential, as homeowners run the risk of wounding their plants by not making careful, precise cuts.

As an example, the best way to prevent crown gall is to avoid wounding plants when pruning or transplanting them.

• Fungicides can be an effective tool for preventing and treating rose diseases. Botrytis blight, for example, can be treated with a fungicide spray, but it should be done as early as possible, before the fungus has had time to spread. An important note is that fungicides must be applied carefully to avoid resistance development.
• Insecticides or horticultural oils can be useful to help control pests, such as aphids, and disease. Viral diseases like the rose mosaic virus can be controlled by systemic insecticides containing antibiotics to prevent infestation of aphids and thrips.

If you want to keep your roses vibrant and maintain other healthy plants on your property, contact Burkholder PHC for more information or to schedule a consultation. Burkholder PHC has a team of experienced, qualified experts that can help homeowners maintain the health and appearance of their roses and other plant life. With years of experience in the field, our team knows how to treat plant health care issues for roses and high value landscape plants.

Bagworms are a common pest in the United States. The bagworm (Thyridopteryx ephemeraeformis) is small, about 1/4 inch long, and very active. Bagworms are the larvae of Psychid moths, a type of moth considered a pest. Bagworms are no threat to humans but can damage plant life and wood structures (such as decks) if left untreated for too long.

Bagworms live their entire life cycles on the plant or tree the insects feed on. Therefore, bagworm activity is probably nearby if you see bags hanging from trees and shrubs during the spring or summer.

Bagworm moths lay eggs on the underside of leaves in spring and summer. Adult female bagworms lay nearly 1,000 eggs in each bag. The eggs then hatch into tiny bagworm caterpillars and spin a series of silk threads that connect them to branches or twigs. Next, the caterpillar creates protective “bags” out of leaves, needles, or flower petals that can be up to two inches long.

Next the caterpillar feeds inside these little cocoons until pupating into an adult moth (or egg-laying female). In this cocoon-like covering, the caterpillars remain dormant until mid-June through early August, emerging as adult moths to mate and produce new generations of bagworms. This cycle repeats every year until killed by cold weather or pesticides.

The bags that bagworms make for themselves are protective but also serve as an effective way for them to move around. When the time comes for them to find a new place, the pests detach themselves from their bag and let the bag fall. When we see large clumps falling from trees like this, we know plenty of bagworm larvae are inside.

Bagworms primarily eat evergreen trees and bushes but can feed on more than 120 species of plants. A bagworm will also feed on ornamental plantings such as maples, conifers, crabapples, and cranberry bushes. These insects are some of the most common pests that attack shade trees in our landscapes.

In rare cases, bagworms will also eat deciduous trees and shrubs. These pests are most commonly found on evergreens such as spruce and pine trees but can also be found on other plants like rhododendron bushes.

Bagworm larvae damage plants by feeding on needles and leaves. Young bagworms feed on the upper epidermis of host plants, leaving tiny holes in the foliage. Damage by mature larvae is incredibly destructive to evergreen plants, such as cedar, juniper, and arborvitae.

Identifying these pests and taking steps to eliminate them before they cause significant damage is important. Because of their unique appearance, bagworms often go unnoticed until the infestation is extensive. Many homeowners are unaware of the presence of bagworms until the pest is in enormous numbers. The caterpillars often build their homes on top of trees or other plants, allowing them to grow unobserved for months or even years.

A plant health care expert can identify a bagworm infestation by finding the telltale silk bags with small pieces of host plant material attached to them. These bags can be any color, from white to brown, typically ranging from 1/2 inch to 3 inches long. Bagworm larvae live inside these protective linings during their development stages.

Luckily, several methods can be used to prevent infestations from occurring in your yard. First, the process involves removing the bags from the trees and bushes. Many homeowners can be anxious or nervous about removing the bags, so working with a plant health care specialist is ideal. After removing the bags, the PHC specialist will spray the plants with a combination of soap, oil, or insecticide and repeat this process to remove any remaining larvae.

Second, a plant health care expert can use insecticides to kill the bagworms in your trees and bushes. The insecticide must contain specific chemicals to eliminate and reduce bagworm populations effectively. The best time to spray is during the early morning hours when temperatures are cool.

Bagworms can be a significant issue for homeowners and their plants. If you want to keep your landscape safe from them, reach out to Burkholder PHC. Our arborists will conduct a plant health care evaluation and diagnosis of your landscape and inform you of your treatment options. Burkholder PHC provides no-cost identification of the situation in addition to free testing, diagnostics, inspections, and evaluations. Contact us today for a free consultation.

What is the spotted lanternfly? If you live in Pennsylvania, you have probably already seen this insect. The spotted lanternfly (lycorma delicatula or SLF) is an invasive species native to China and Southeast Asia.

The pest was discovered in Pennsylvania in 2014, specifically Berks County, and has spread throughout Pennsylvania and neighboring states: north to Massachusetts, south to North Carolina, and west to Indiana and Michigan (See the Spotted Lanternfly distribution map for the mid-Atlantic area). The spotted lanternfly feeds on and damages many different plant species.

Many homeowners have reported sightings and damage from this pest, both direct damage by feeding and secondary damage due to excessive sooty mold formation on lanternfly excrement (honeydew). As part of our series on invasive insects, here is what you need to know and what you can do if you spot the colorful insect around your property.

As of 2023, the spotted lanternfly is reported to be found in 51 Pennsylvania counties and can build to astounding numbers when left unmanaged. While many Pennsylvania residents have spotted this invasive species on their landscapes, we have some information to help those who want to keep their landscape free from invasive insects.

Adult spotted lanternflies can be identified by their coloration and bodies. The insect has grayish wings with black spots; the tips are black and gray, while the bodies are black. When flying, spotted lanternflies will show vibrant red hind wings. Adults are around 1 inch long and a half-inch wide with wings folded. They can jump several feet when startled or approached.

You can also identify the pest via their egg masses or nymph stage. Egg masses are typically found on tree bark on the underside of scaffold branches and occasionally on other smooth surfaces such as rocks, outdoor furniture, and even vehicles. The mass is usually around 1 inch long and a half to three-quarters of an inch wide, with a gray-brown, mud-like covering.

Spotted lanternfly nymphs are much smaller than adults, only about 1/8 to 1/2 an inch long (depending on instar: a phase between two periods of molting in the development of an insect larva or other invertebrate). However, nymphs have distinct coloration: initially black with white spots and wingless, developing red patches/red patches and white spots as they mature.

Spotted lanternflies feed on plant sap, and at a high population, this can cause significant damage to an area’s plant life. While known to feed on over 70 different plants, spotted lanternflies have strongly preferred the tree of heaven (ailanthus altissima), grapevines, maple trees, black walnut, birch, willow, and styrax.

Feeding on tree and plant sap can cause wilting, leaf curling, and dieback. In addition, as the SLF feeds on plant sap, the insect excretes a sugary substance called “honeydew,” which can attract bees, wasps, and other insects, and promotes the growth of sooty mold, which causes further damage to plants.

Here are the months each life stage occurs to help you better identify the plant pest on your property.

Egg masses: The invasive pest usually lays eggs from September to November, and lanternflies spend the winter as eggs.

Nymphs: Nymphs will first hatch around May to June and mature until around July to September.

Adults: July to September is when most spotted lanternflies have matured into adults; mating and egg-laying can continue until December.

The insect has become so prevalent that Pennsylvania has put affected counties under quarantine to stop the movement and slow the insect’s spread to new areas within or out of the current quarantine zone. The quarantine involves traveling and transporting outdoor items.

If you see any spotted lanternfly or signs of its damage on your property, contact Burkholder Plant Health 

Care (PHC). Burkholder PHC treats for spotted lanternflies as part of our plant health care program. Our plant health care program emphasizes proper diagnosis and precise treatment, using only state-of-the-art, research-backed methods and equipment. We also utilize various pest management and control processes to protect your landscape from invasive, harmful pests.

For more information about spotted lanternfly issues in Pennsylvania, you may wish to visit the following resource links.

Cooperative State Program Homepage

Cooperative State Program Map

Pennsylvania Quarantine Details/Updates

Pennsylvania Quarantine Map

Mid-Atlantic SLF Distribution Map

If you want to keep your landscape beautiful, healthy, and free of spotted lanternfly, contact Burkholder PHC for a consultation. Our team of plant health care professionals has decades of experience helping homeowners keep their landscapes as healthy and vibrant as possible. In addition, we have up-to-date knowledge of the latest plant health care methods, from pest control to soil care and more. For more information on our services, contact us today.

Boxwood leafminer is a common pest that affects boxwood shrubs. These pests appear as tiny flies on the undersides of boxwood leaves and cause significant damage to boxwood shrubs by feeding on the leaf tissue. The species was first reported as a pest in the United States in 1910 and is now found across the United States wherever boxwood grows.

Adult boxwood leafminers are small, less than 1/16 inch long, have a yellowish-orange coloration, and are similar to gnat-like flies. These leafminers have two pairs of wings and six long, thin legs. The eggs are white to transparent and hatch into small whitish or lemon-yellow 3mm long larvae or maggots. These larvae initially lack any legs, but they gain legs as they age.

The life cycle of boxwood leafminer is broken down into four stages: egg, larva (or maggot), pupa, and adult.

1. Egg: Females lay eggs on the undersides of leaves in summer. They hatch into larvae within about two days. On average, females lay around 29 eggs and die soon afterward. The eggs take anywhere from 14-21 days to hatch.
2. Larvae: Larvae emerge from the eggs after hatching. Then the larvae feed on the leaves the remainder of summer through early fall. Larvae pupate in late winter.
3. Pupa: Pupating is a stage when insects transition from larvae to adults. Eventually, the leafminers emerge in May.
4. Adult: Adult leafminers mate soon after emerging and the females deposit their eggs in new foliage by thrusting a curved needle-like ovipositor through the lower surface of the leaf, and the cycle repeats.

The boxwood leafminer damages the leaves by laying eggs on them, which, as mentioned previously, hatch into larvae that feed on the leaves until maturing into adults. The laying of the eggs and the larvae feeding on the upper and lower leaf surfaces causes leaf blisters on the infested leaves. These blisters can become discolored and leaf drop may result.

Homeowners may see premature leaf drop (when green leaves turn brown before falling off), stunted growth, and yellow spots in some areas where leafminers have been feeding.

To manage and control infestations, a plant health care professional needs to identify the presence of leafminers by examining a property. Once identified, our expert can prune and dispose of heavily infested branches to prevent the spread of the infestation.

Systemic insecticides, soaps, and horticultural oils can effectively control leafminers. These pesticides and insecticides should be cautiously applied.

Because these pesticides can have adverse side effects on other plants or beneficial insects, a plant health care expert should be the one using these treatments. In addition, proper cultural practices, such as regular pruning, fertilization, and irrigation, can help prevent and minimize boxwood leafminers’ impact.

If you want to keep your plants healthy and prevent the damage boxwood leafminer populations can cause, contact Burkholder PHC for a consultation. We are a team of certified professionals with decades of experience caring for and maintaining healthy plants and trees for Main Line residents. In addition, we have up-to-date knowledge of the latest and best practices on plant health care and pest control methods. For more information on our services, contact us today.

Invasive insects can be a threat to your lawn and home. In addition to disrupting or harming residential landscapes, many invasive pests negatively impact local environments if these insects spread and reproduce. Therefore, pest management is crucial to protecting landscapes and preventing these species from damaging lawns as much as possible. This article will highlight how these insects can spread and which species we will discuss in future articles.

Insects can spread in several different ways. Some species can fly long distances, while others rely on the movement of infested materials such as plants or wood products. Movement of infested materials can involve humans or animals carrying them from place to place on their bodies or clothing and through contaminated food or water. In some cases, invasive insects may be carried along with other products, such as fruit trees and lumber logs, known as “hitchhiking.” Some invasive species may even travel across oceans by hitching rides on boats.

The spotted lanternfly is an insect introduced to the United States in 2014, native to China and India, that has since spread to 14 states including Pennsylvania, New Jersey, Virginia, and Delaware. The spotted lanternfly feeds on various tree species, including fruit trees like apples and grapes and hardwood trees like maples and willows. This pest leaves scars on leaves by feeding on them, which can interfere with photosynthesis. Other damages caused by the spotted lanternfly include dead shoots at the ends of branches, dieback or defoliation, reduced tree growth rates, and increased susceptibility to disease outbreaks.

An emerald ash borer is a metallic green beetle that feeds on ash trees. The insect was first discovered in the United States in Michigan in 2002 and has since spread to at least 30 states. Emerald ash borer has killed tens of millions of ash trees in the United States. The wood-boring beetle infests ash trees and feeds on the inner phloem, cambium, and outer xylem, causing crown dieback, bark deformities, D-shaped exit holes, woodpecker feeding holes, and yellowing foliage.

The Japanese beetle is an invasive insect species that feeds on the roots of turfgrasses found in home lawns, golf courses, and athletic fields. This species of beetle has a striking appearance. The head and thorax are metallic green, the abdomen is metallic green with black spots, and the legs are dark green.

Balsam woolly adelgids are small wingless insects that infest and kill fir trees, mainly balsam fir and Fraser fir (common Christmas trees). The adelgid feeds on the tree’s needles, causing them to turn brown, die off and fall off the tree prematurely. Balsam woolly adelgids are native to Europe and were first detected in North America around 1900. Since then, they have spread across the United States and have caused extensive damage to mature stands of balsam fir trees.

If you are concerned about invasive insects harming your landscape and want to keep your property safe, contact Burkholder PHC. We provide a free evaluation from our highly experienced, qualified plant health care experts to help remove and control various invasive insect species and any adverse effects these pests may cause. Contact Burkholder PHC today for a free consultation.

Soil amendments are products added to the soil to improve soil’s physical, chemical, or biological properties. Some of these properties that amendments are used for include increasing soil fertility or water-holding capacity and decreasing compaction or erosion. Soil amendment differs from fertilizer by modifying the condition of the soil itself, whereas fertilizer adds nutrients to the soil.

There are also 2 general categories that soil amendments fall under: organic and inorganic.

Organic soil amendments are composed of materials that were previously living matter. In contrast, inorganic amendments are made of mined or artificially created materials.

• Wood chips
• Grass clippings
• Compost
• Manure
• Sawdust

• Lime
• Gypsum
• Rock powders

One reason to use soil amendments is to alter the soil’s pH. The soil’s pH level needs to be within a specific range to give plants adequate access to nutrients. For example, some plants prefer more acidic soil, while others thrive in more alkaline soil. You will need to have a plant health care specialist test your soil to determine its current pH and what treatment is required to help your plants’ health.

Regarding the time of year, soil amendments can be applied at any time, but the ideal times are early spring or late fall. This is because soil amendments are more easily incorporated when the soil is bare and dry. If you apply them in the spring, they will be more effective at helping your plants grow because you will be fertilizing your plants and improving the soil. When soil amendments are applied in the fall, they will have time over winter to break down and become part of the soil before you plant again in spring. The types of soil amendments used also differ depending on the season.

During spring, we recommend a potassium-only fertilizer with the necessary nutrients. This helps improve the plant’s resistance to stress factors such as disease pressure, extreme temperature fluctuations, and drought conditions. In addition, this systemic nutrient formulation stimulates health and vigor without triggering excess physical growth.

During the fall, plants absorb and store nutrients for the initial spring growth period. As a result, supplying the nutrients often lacking in landscape soils is vital. We fertilize with a slow-release fertilizer to ensure the availability of essential macro and micronutrients. This amendment also gives plants and trees the sustenance necessary for healthy growth and resistance to insects, disease, and harsh environmental conditions.

One of the benefits is restoring your soil’s pH balance. If the pH balance of the soil is too high or low, certain nutrients (potassium, nitrogen, and other elements) become more difficult or less available for plants to absorb, which can negatively impact the health of the plants. As a result, plant health care experts will use soil amendments to modify the soil’s pH balance.

Some of the other benefits of soil amendments include the following:

• Organic materials in soil amendments help encourage plant growth.
• Soil amendments help improve aeration, prevent soil compaction, allow air to flow more freely, and improve the soil’s drainage.
• Organic soil amendments can improve certain soils by improving the soil’s ability to store nutrients and water.

If you want to keep your plants and trees healthy with soil amendments, contact Burkholder PHC. We offer many plant health care services in addition to soil care, such as plant growth regulators, plant pest control, and more. In addition, our team of specialists has years of experience maintaining the health and vibrancy of landscapes in the Main Line area. For more information about our services, request a free consultation today.

Invasive species are plants or animals from another region that have been placed in a new environment. Often these species are introduced to an area by humans and can spread quickly and cause damage to native ecosystems and people. While not all invasive species are necessarily dangerous or lethal, some of these plants and animals can disrupt the balance in their new environments.

Invasive species have traits that allow them to thrive and spread over their new environment rapidly. Some of these include

• Ability to grow quickly
• Ability to reproduce quickly
• Ability to disperse a high number of seeds or spores quickly
• Ability to alter form to suit current conditions
• Tolerance of a wide range of environmental conditions
• Ability to sustain a diet of various food types

Invasive species are often overlooked because those unfamiliar with these plants and animals do not perceive them as threatening. However, these plants will take over large areas of land over time. A well-known example of an invasive plant is the kudzu vine (Pueraria lobata). Kudzu was brought from Asia into the United States as a food crop during the late 19th century. The vine spread throughout many southern states in the U.S. and chokes out surrounding plant life.

Invasive species can be challenging to remove once established. One of the reasons is the lack of natural control mechanisms. In their native environment, plants and animals have predators or environmental factors that act as control mechanisms to keep populations in check.

For example, the spotted lanternfly is an invasive species of planthoppers native to China. In China, the lanternfly is preyed upon by native species of wasps. However, those wasps are not found in Pennsylvania, so the spotted lanternfly has spread rapidly because those predators are unavailable to keep the population in check.

The most common way invasive plants spread is by being sold at nurseries. In some cases, many invasive plants often lack labeling that indicates whether the plant is native or exotic to a specific region. As a result, governments are taking more action to prevent certain invasive species from being sold at nurseries.

If you are purchasing plants for your landscape, you may wish to check to see whether the plant is native or could have negative impacts on your landscape. If you are concerned about invasive species of plants and insects on your property, contact plant health care experts to assist with removal efforts.

Invasive species are difficult to remove, as removing or controlling their population requires extensive knowledge of the specific species and the various control and removal methods. These methods also have to protect the health of other plants in the environment.

Invasive species can threaten local ecosystems, and some have the potential to cause harm to native wildlife and people. Visit next month as we continue our series and discuss invasive plants. Burkholder PHC has experience helping homeowners in the Main Line area with all types of plants and insects. We have a team of specialists who will visit your property, conduct a plant health care evaluation, diagnose the problems, and inform you of the recommended treatment options. Contact us today for a free consultation.