Black Knot Fungus

Photo credit: Tricia. Simon

As describes “Black Knot is caused by the fungus Aspiosporina morbosa, is a very common disease of plants in the Genus Prunus” (Ramen.Samantha

It effects popular trees like the Mayday Tree, Amur Cherry, Nanking Cherry and Flowering plum. All of these trees come from the “flowering plant in the Rosaceae family” ( The fungus typically starts in April to June as it becomes more aggressive in the wetter months. It looks like blistering sections of the lower trunk and hanging dark burned sections of the upper canopy. It tends to build up within the crotches of the vectors and can spread quickly with low airflow. Black knot fungus can been seen best in the winter when foliage has been shed and the contrasting colors can bring out the blistered effected areas. This fungus can be spread easily by flying insects or birds visiting the canopy, improper pruning practices, improper removal of cuttings, or simply planting too many of one species. The dark “gulls” ( are the result of the fungus spores landing on the area and the infection taking place. The final result is a blister 5 cm to 10 cm that eventually girdles the branch and eventually dies. Black Knot Fungus not only grows externally but internally as well, this can be spotted within the trunk

Example of black knot fungus on tree trunk Photo credit Bogorus. Paul

the fungus” (Ramen.Samantha The fungus develops in the stems beneath a thin film layer of moisture generally where a new leaf starts. The fungus can be moved around the plum and cherry trees by the wind and the new leaf growths make a pefect landing area.  Proper pruning practices need to be taken into effect and proper disposal of cuttings is the only way to prevent the Black Knot Fungus from spreading.


After the flood of 2013 there was plenty of moisture to be had in southern Alberta, Calgary area specifically shown a drastic increase of the airborne fungus within the prunus family. With the commotion of the flood in 2013 city crews and local arborists were spread thin on flood clean up. The following year showed the similar moisture patterns and again caused the fungus to spread along with many communities planting the same tree in every lot. As Richard Pootmans of Ward 6 Council explains “we lost 50 trees within discovery ridge this spring and there are more flagged on the boulevards every week”. (Moxley. Karen CBC news May 8, 2014 Local arborists were overwhelmed along with 311 calls from concerned citizens. As Matthew Davis explains “ I would say a good 40 percent of the work we did in the last eight months has been black knot related, the Schubert Chokecherry and Mayday trees are so commonly planted” (Moxley. Karen CBC News May 8, 2014 The dieses was first described in 1821 in Pennsylvania has spread across north America ( Calgary since the 2014 outbreak has diligently run add campaigns and commercials to educate citizens on how to properly prune and dispose of cuttings. There also have been cost sharing agreements between the city and the community association to remove and replant the infected trees. The city of Calgary has been ranked sixth greenest city with the most green space per kilometer (Pretty. Brad May 15, 2018 John Borrow of the Calgary parks explains on preserving the green space in Calgary, “Our green spaces provide enhanced aesthetics and health to our city, many developers and city planners have learned the important lesson to plant diversely.” (Moxley. Karen CBC news May 8, 2014 As this season in southern Alberta shapes up to bet wet and mild many communities are keeping a look out for black knot fungus spreading on remaining trees.

Arborist in the city of Red Deer performing spring pruning. (Photo credit Michelin. Lana March 22, 2019)


The loss of such trees in the Prunus Genus family is always heart breaking. They bring an enhanced beauty to a local park or boulevard. Trees also bring privacy and increased value to properties when properly placed and planted. As well trees need to be producing at maximum potential in orchard situations. Because of the bloom cycle of these trees the bees also benefit from an excellent source of food while the trees benefit from thorough pollination. Bees play such an important role within our production of food that we need to promote proper planting and fertilizing techniques. Diversity is key in keeping our trees longer and preserving investments. It is always a shame when rows of trees need to be replaced, the cost of removing the trees then grinding each stump presents four problems.

  • The loss of tax dollars and future budget fluctuations for parks and rec for towns and cities.
  • The loss in seasonal growth per tree lost example removing a ten-year-old tree and replacing with a four-year-old tree.
  • The loss of food source for bees, birds and other animals.
  • The loss of aesthetic and morale when trees are removed.

Though this brings business to local arborists and city works it is a reminder that the actions of today effect the outcomes of tomorrow. Diversity promotes more types of animals and landscape growth than anything else on the planet. This ensures that funguses and blights do not gain the upper hand when properly managing trees and shrubs. Protecting the investments in parks made by cities and towns has been a rising concern as the city of Calgary has planted approximately 7 million trees in public and private land ( Along with programs like Arbor Day which happens every year on May 2, grade 1 students are sent home with tree seedlings which to date has distributed 425 000 tree seedlings. ( With programs like these it brings together communities, Landscape And Nursery Trades Association along with Alberta Sustainable Resource Development.

Arborists cleaning up trimmings in the city of Toronto (photo credit Katsarov. Christopher Globe And Mail, August 8, 2016


Mitigating the black knot fungus may seem like a daunting task to home owners but with simple pruning, disinfecting and disposal practices the fungus will be kept under control.

First ensure that you are properly prepared to prune the tree this includes:

  • A pruning saw (straight or curved)
  • Loppers or hand pruners
  • Pole pruners or loppers
  • A small step ladder
  • Disinfectant either rubbing alcohol or bleach diluted with 70 percent water.
  • Clean rags
  • A large bag for cutting (to be disposed of in the landfill)

Please note DO NOT use a folding ladder for pruning this is frowned upon within the industry and mostly your safety. An orchard ladder is the safest way to prune a small residential tree but extreme caution should be exercised. If the pruning requirements are taller than a pole lopper and a step ladder a professional arborist should be contacted.

Pruning is best done in the winter months when the fungus is easy to spot and is in a dormant stage. Caution must be used in the wet spring months when the fungus is most active, slow precise pruning is needed to prevent the spread of fungus. Pruning out black knot fungus requires that the affected area be trimmed two to five inches back from the “gulls”. Once this has been completed cutting can be burned safely within a fire pit, buried in an open area, or disposed of in a local landfill. DO NOT dispose of in brush pile or compost as the fungus will continue to spore given the right conditions. Lastly disinfect all tools and rake turf and ground, if the tree has large amounts of black knot fungus disinfecting will need to be done after every cut. In regards to proper pruning cuts they need to be clean, minimal bark tear and safe for future growth.

Example of a proper pruning cut to remove black knot fungus
(photo credit “how to prune black knot”


In terms of larger scale tree plantings such as city streets, nursery’s or orchards larger scale pruning practices need to be applied. First the fungus needs to be monitored right from the planting of the tree. History has shown that mitigation of this fungus gives a far better chance for the trees survival into its older years. For example, if a section of a boulevard in a city has ten out of the fifteen Maydays effected by black knot fungus, removals must be done in the winter months. This limits the number of active spores in the atmosphere spreading throughout the neighbourhood. Generally, arborist contractors use tow behind chippers to maximize the number of trees removed, these machines must be cleaned and disinfected at the end of the day. The chips must be hauled away to a local landfill, generally they are disposed of in the main dumping area not the woodchip piles.

If replanting is approved stump grinding will take place once the frost leaves the ground. Please note that the area will need to be left for a season for the remainder of the tree to fully die within the soil. When replanting variety and height clearance must be taken into consideration along with proper spacing to allow maximum canopy growth.

Within nursery’s and orchards consistent diligent pruning must be performed regularly to combat the fungus. Starting either uphill or upwind and working your way down limits the exposure to other trees. Tools must be cleaned regularly and cuttings either burned, buried or disposed of in the landfill. If an area becomes unmanageable of the black knot fungus consumes 30 percent of a tree a removal must be issued.

Diversity should always be considered within the replanting process.

Example of commercial stump grinding (photo credit



I just wanted to extend a thank you to the wealth of knowledge available today within the internet and communities.


photo credit Bogorus.Paul

Ramen, Samantha

Moxley.Karen CBC news May 8, 2014

Pretty.Brad may 15, 2018

Moxley. Karen CBC news May 8 2014

Photo credit Michelin. Lana March 22, 2019

Photo credit Katsarova. Christopher Globe and Mail August 8, 2016

Photo credit “how to prune black knot”

Photo credit



Nutrition and fertilization Reflection

It is April 2019 and this week brought a new perspective to our jobsite, by further expanding our knowledge on the process of fertilizing our local turf and woody plants. We regularly use an organic slow release lawn rebuilder to beatify turf that has either too much compaction or poor soil content. As we looked at our local trees both my co-worker and I discussed what nitrogen deficiency looked like in various types of trees. Even though it is early in the season we could look at the last seasons growth from the node and the size of bud expected. Through further research we discovered that the average soil content in this area contains higher salts which effects the growth throughout the summer. It was interesting to see on visual inspection which trees were benefitting from these findings. There were other factors including poor soil drainage and improper positioning on properties. We looked at the nutrient ratios on the fertilizer packaging and confirmed that we could also broadcast seed the affected trees. With is being a slow release formula we are able to avoid the dreaded fertilizer burn that generally upsets clients. We also tossed around the idea of drilling various holes around the trees and filling them with the product, this in turn may provide faster results as the turf does not consume a portion of the product. We will continue to experiment with the best effective method as the summers can be harsh on the parries.

3 Tips for your properties landscaping

Importance of proper drainage on every property

The greatest danger in any landscape is having inadequate drainage away from structures or walls. By directing runoff and ground water to proper run off areas you will prolong the investment of your landscaping and property.  Improper drainage can cause soil erosion, flood your structures, have a poor effect on vegetation growth and result in standing water. Luckily there are plenty of quality products to mitigate this problem, along with experienced landscapers like ourselves to install and accommodate your property.

Proper planting distance for trees and shrubs

Strategically placed trees and shrubs will beautify a proper and bring summer shade resulting in a cooler home. As will they protect from wind, increase property value and curb appeal. However by doing this there are a few basic rules of thumb to follow. If the tree can reach the height of 20 feet then it must be placed 10 feet from any structure or lines. This allows for root growth without having foundation issues, and clearance overhead for pruning purposes. If the tree can reach the height of 20-60 feet then it must be planted 15 feet from any structure or lines. If you are planting multiple trees shrubs are recommended 6 feet apart, small deciduous trees 8-10 feet, and large trees 10-18 feet. By doing this you will create an effective windbreak along with an even growth pattern.

Sod vs Hydroseeding

Both sod and hydroseeding have great benefits for completing a project or property. Typically in our climate of southern Alberta there are a few things to consider. Considerably more water is needed to establish a hydroseeded lawn. If the weather is hot and dry after application, you may need to water several times a day for six to eight weeks. Sod is more forgiving, since you are not dealing with new seedlings that are prone to drying out. As well with hydroseeding it tends to dry out more regularly with our wind prone region, this promotes weeds and soil erosion. If an area exceeds 3000 square feet hydroseeding is a valuable option, but surprisingly requires for care to become successful. Sod is definitely a premium choice but provides a completed project, hillside and soil control and less established weeds in our environment.

Tree Services Article

Dangerous Tree Examples

Though trees may be beautiful all times of year they do have a tendency to become dangerous if there is two co-dominant stems resulting in a crack in the crotch. This will become a safety hazard and needs to be mitigated safely and effectively.

Rigging and Safely pruning

Some trees eventually grow bigger then expected and encroach on buildings and powerlines. In this case rigging will have to be used to ensure the job is completed safely, we are in the process of taking high risk rigging courses to be ready for any challenge.

Hedge Box Blight and other airborne fungal

Trimming your hedge regularly ensures that it will flourish over the growing season and mitigate fungal. However in humid conditions box blight or Volutella Blight can begin to thrive. Good air circulation and trimming the effected areas immediately is the first line of defence. All tools used to prune must be disinfected after and all trimmings must be removed from premise. We have been trimming infected hedges for a number of years and have successfully been able to decrease the blight affection within a year.

Fall Tree Removals

There are plenty of reasons the trees need to be removed, obvious ones are a dangerous lean that encroaches on structures and walkways or a tendency to drop leaves or sap on roofs. There are not so obvious reasons like cracks in the main trunk or leaders, infestations of insects or disease, the tree has formed a bad crotch and may split overtime. Whatever the reason it is best to call a certified arborist as they are trained in the safest most effective way to remove them.

At Dreamscapes Earth Management we are very experienced and have you covered for all your tree pruning, removal and planting needs.  If you need any of the following services do not hesitate to give us a call

Fall Tree Pruning

Late Fall/winter is the perfect time to prune various trees and hedges, as the seasons shift from the hectic pace of summer trees, much like us, begin the slowdown process.
They begin to loose their leaves and become dormant. This is a perfect opportunity to look at how the new growth has effected the trees clearance on buildings and walkways. It is also a perfect time to mitigate disease management, as there is great visibility with no foliage on the branches thus creating a precise prune opportunity. This gives a foundation for future growth and creates an excellent time to promote a much higher bloom in the spring time.

At Dreamscapes Earth Management we are very experienced and have you covered for all your tree pruning, removal and planting needs.  If you need any of the following services do not hesitate to give us a call

Fall Landscaping and Hardscaping

So another Summer has gone but do not despair! Fall can be a great time to update existing landscaping or create new areas to enjoy.
As the garden beds become dormant they can easily be extended or changed without causing detrimental damage to plants and trees.
It is also a great time to reflect on water consumption of these areas and mitigate for future use and drought conditions. This means that mulch or grading can be installed to aid with the conditions that summer brings. It is also an excellent time to consider fire protection especially on acreages where fire response varies, this includes creating fire breaks within the property and ensuring thick overgrowth is mitigated properly. Also Fall is a great time to asses that there is a safe clearance of trees around structures and mulch and other flammable material is used and applied safely around buildings. It is also a great time to repair patios that may have shifted over time to ensure they are at grade and can shed water/ice over the winter months.

Taking Care of Your Garden in the summer

Grass Care

With the extreme heat that we all have experienced this summer, it is important to consider proper grass maintenance. With water restrictions in full force, the dry ground has caused most grass types to go dormant. Considering the lack of water this year the grass will restore itself next season.

If the grass needs to be cut it is important to consider the height of the mower deck. Grass should only be cut at a minimum of 2.75 inches, as well people should refrain from cutting once a week. Fertilizer should not be added as it can either burn or be non-effective to the grass at this time. Cutting at a taller height helps protect grass roots and ensures a healthy rejuvenation next season.

Tree and Shrub Pruning

This season the trees and shrubs have been stressed with the lack of water and early spring we experienced. It is in the trees and shrubs best interest to refrain from pruning from the hot summer. Leaves help keep the tree cool. That being the said pruning helps prevent disease such as black knot, fire blight, honey locusts and beetles. Prune wisely.

It is important to consider proper watering times for newly planted trees, saplings and shrubs. Watering should only be done in early morning and late evening, this ensures that the will penetrate the root system. Mulch is one of the most important tools to keep your trees healthy any time of the year, especially during the hot summers. Most arborists suggest applying mulch in a layer that is around two to three inches thick on top of the soil by the tree. Ideally, you want to be able to see the tree flare, the area where it widens when meeting the ground. Put the mulch right outside of this area or around six inches from the tree’s trunk.
Mulch serves two important purposes during the summer. It helps the soil retain the moisture by preventing evaporation and it reduces the overall temperature of the ground. Since hotter ground can be harder on the tree’s roots and simply absorb more water.

Garden Care

With the long hot days most plants have shut down, even tomatoes have stopped pollenating. It is important to refrain from fertilizing as the garden is not absorbing much with the heat and can burn the plants. Ironically, during the heat of midsummer, sometimes the best thing you can do is to leave your plants alone. If you are going to water it is best to stick to a schedule of an inch of water inch of water morning and night. By doing this it helps conserve water and ensures you are not over watering plants. It is always best to work with mother nature and she will support your efforts.

3 Steps to Greener Lawn This Summer


To keep your lawn looking stunning there are regular steps that can be taken to ensure your grass looks stunning all season long!

  1. Fertilize

Fertilizing is essential to a greener lawn.  It strengthens the roots, helps promote new growth and can help keep weeds at bay.

  1. Irrigation

Water is essential for all living organisms so your grass is no different.  Under watering will turn your grass brown and over watering will drown the roots.  There are pockets of space under the grass in the ground that usually fill with oxygen.  If you over water the grass these pockets will instead be filled by, you guessed it, water!  Oxygen is imperative as without it the roots of the sod will suffocate and your grasses root system will be weakened

  1. Mowing

It is very important to regularly mow your lawn and mow it correctly.  Not just any mowing technique will be sufficient. The mower blades should be sharp to ensure a nice clean cut.  Also the height you cut the grass at is important. You do not want to cut the grass too short as this puts extra strain on the roots.  This will make the root system weaker and can lead to more weeds. You should generally only cut the grass down by 1/3.

At Dreamscapes landscaping we can help you maintain your lawn so it looks great all season long.  We cover Okotoks, Calgary, Black Diamond, High River and more.  If you need a quality, reliable and affordable lawn maintenance program or lawn cutting service contact us today for a free consultation.