Common Tree Diseases Every Trainee Arborist Should Know

In more than 45 years of tree work across Kent and the South East, we have seen how quickly a single infection can change the condition of a tree. Recognising disease is part of the job, not an optional extra. Whether you are thinking about a career in arboriculture or brushing up before an assessment, these are the problems you are most likely to meet on British sites.

Ash Dieback

Caused by the fungus Hymenoscyphus fraxineus, ash dieback has spread through woodlands across the country since it was confirmed here in 2012. Look for blackened leaves wilting early in the season, diamond-shaped lesions where branches meet the stem, and crown thinning that works from the top down. Infected ash turns brittle and behaves unpredictably under load, which makes it one of the riskier species to work on. No one should climb a heavily affected ash without a proper assessment first.

Honey Fungus

Honey fungus, or Armillaria, attacks the roots and lower trunk of a wide range of species. The clearest signs are honey-coloured toadstools at the base in autumn, a white fungal sheet beneath the bark, and black bootlace strands running through the surrounding soil. It travels underground between hosts, so one infected tree often points to a wider issue across the garden or site.

Bleeding Canker of Horse Chestnut

Dark, sticky fluid seeping from splits in the bark is the giveaway here. The bacterium Pseudomonas syringae pv. aesculi is usually responsible, and over time the cankers can girdle the stem and bring on crown dieback. Plenty of trees hold on for years, so felling is rarely the first answer.

Phytophthora Root Rot

Phytophthora species thrive in wet, poorly drained ground and rot the root collar. Above ground you will notice sparse foliage, undersized discoloured leaves and slow decline. The soil is where the trouble starts, which is why drainage work often forms part of the remedy.

Learning to Spot Disease on Site

Photographs in a textbook only take you so far. Our courses put you in front of real trees in real conditions, where you learn to read the whole tree rather than one symptom. If you are ready to begin, get in touch and we will talk through the right route for you.

How to Deal With Tree Pests

Tree pests cause more damage across the UK than most people realise. We see the results every week on sites around Kent and the South East, and the pattern is nearly always the same. A problem that could have been sorted in an afternoon turns into a felling job because nobody noticed it in time. Here is how we approach it.

Learn to Read the Warning Signs

Trees rarely fail without warning. Look for thinning foliage in the upper crown, leaves that yellow or drop out of season, small exit holes in the bark, sawdust-like frass around the base of the trunk, and sticky honeydew on the leaves or on anything sitting beneath the canopy. Webbing, silk nests and visible larvae are obvious enough. The subtle signs matter more, because they show up first.

Identify What You Are Actually Dealing With

Treatment depends entirely on the species. Oak processionary moth is a public health concern as much as a tree health one, and the caterpillars must never be handled or disturbed without proper protection. Horse chestnut leaf miner disfigures foliage but rarely kills. Bark beetles attack the vascular system and move fast. Aphids and scale insects weaken a tree slowly over several seasons. Getting the identification right saves time, money and often the tree itself.

Act Early and in Proportion

Once you know what you are facing, match the response to the severity. Light aphid activity on a healthy specimen usually needs nothing more than monitoring. Localised infestations can be pruned out, with all arisings chipped or disposed of on site so the problem does not travel to the next job. Targeted treatments have their place, though they should only ever be applied by someone qualified to do so.

Improving conditions at the base of the tree does far more than people expect. Mulching, soil decompaction and sensible watering all help. A tree in good health fights off pests largely on its own.

Know When to Bring in a Professional

Some work is not a do-it-yourself job. Anything involving oak processionary moth, pesticide application, climbing, or a tree close to a road or building needs a qualified arborist. Legal duties around protected trees and notifiable pests apply too, and getting that wrong is costly.

Build the Skills Yourself

If you work with trees for a living, pest recognition belongs alongside your practical tickets. Our courses cover safe working, chainsaw competence and climbing, and the Qualified Arborist Suite takes you from beginner to employable in six weeks. Get in touch and we will talk it through.

Tree Felling Course

Felling a tree is the moment where preparation either pays off or catches you out. Our tree felling course teaches you to read the tree, plan the cut and bring it down where you intended, every time. We deliver the City & Guilds NPTC Level 2 Award in Chainsaw Maintenance and Cross-Cutting and Felling and Processing Trees up to 380mm from our base at Preston Farm in Shoreham, and we train on real timber rather than practice logs in a yard.

We are the DTE Academy, the training body for Down To Earth Trees Ltd. We have been felling trees commercially across Kent and south-east London since 1979, and everything we teach comes from that daily working experience.

What You Will Learn

The course builds from the ground up, so no previous chainsaw experience is needed. You will cover:

• Daily and routine chainsaw maintenance, including chain sharpening, fuelling and oiling

• Cross-cutting timber under tension and compression, with the pivot points and swing directions that decide where a stem moves

• Site assessment and risk assessment before a single cut is made

• Sink cuts, hinge wood and back cuts, and how each one controls the direction of fall

• Snedding and de-limbing felled stems ready for processing

• Dealing with hung-up trees using hand tools

• Health and safety legislation, exclusion zones and safe working practice

Our assessors verbally examine you at the end of the training. Pass, and you receive an NPTC Certificate of Competence, which is the qualification employers and insurers across the industry expect to see.

Who Should Take This Course

The course suits anyone whose work involves felling trees up to 380mm in diameter. That includes people starting out in arboriculture, groundworkers moving into tree work, forestry and estate staff, landowners managing their own woodland, and employers sending crews for certification or refresher training.

We do ask every candidate to complete a short selection questionnaire before booking, and sometimes a brief phone call. This is simply so we can group students sensibly and give everyone a course that works at the right pace.

What We Provide

Chainsaws are supplied. PPE can be hired from us for £40 if you would rather not buy your own kit yet, and we will tell you exactly what to bring if you do have it. Hot breakfast, lunch and drinks are provided throughout the day, because good training happens as much over a brew as it does on the stump.

Book Your Place

Group sizes are kept small and dates fill quickly. View our upcoming courses to book online, or get in touch and we will talk you through the right starting point.

If you are training from scratch with a career in mind, our Qualified Arborist Suite takes you through felling and everything else across six weeks, with a job offer waiting at the end.

Tree Disease Treatment

Trees rarely fail without warning. Long before a limb drops or a crown thins, there are signs that something is wrong, and knowing how to read those signs is one of the most valuable skills an arborist can hold. At the DTE Academy, we train people to recognise, assess and act on tree health problems as part of a working career in arboriculture.

Tree disease treatment sits at the heart of professional tree care. It is not simply about removing what looks unhealthy. It is about understanding what is happening beneath the bark and in the soil, then choosing the right course of action for the tree, the site and the people around it.

Why Tree Disease Treatment Matters

Our parent company, Down To Earth Trees Ltd, has managed trees across Kent and south east London since 1979. In that time we have seen how quickly a small problem becomes a serious one when it goes unnoticed. A diseased tree in a garden, school grounds or a busy street is a safety issue as much as a horticultural one.

Clients depend on arborists who can explain what is wrong and what happens next. That confidence comes from proper training and real site experience, which is exactly what we build into every course we run.

Common Tree Health Problems in the UK

British trees face a growing list of pests and pathogens. The ones you are most likely to encounter include:

• Ash dieback, which has changed the landscape across the south east and continues to drive large volumes of removal work

• Honey fungus, a root disease that spreads through soil and affects a wide range of species

• Phytophthora, which attacks roots and stems and often shows first as bleeding cankers

• Oak processionary moth, a pest with implications for both tree health and public safety

• Bacterial and fungal cankers, which weaken structure over several seasons

Each requires a different response, and misreading one for another leads to wasted work or an unsafe outcome.

Where Treatment Fits Into Tree Work

Treatment can mean targeted pruning to remove infected material, soil decompaction and amelioration to improve root conditions, sanitation to limit spread, or planned removal where a tree can no longer be retained safely. Sound decisions rest on accurate assessment, and accurate assessment rests on knowing your species, your pathogens and your equipment.

Our practical courses give you the ground skills that make this work possible. The City & Guilds NPTC Chainsaw Maintenance and Cross-cutting course covers safe processing of infected timber, while our Tree Climbing and Rescue course prepares you for aerial inspection and crown work.

Start Your Career in Tree Health

If you are beginning from scratch, our six week Qualified Arborist Suite takes you from no experience to a qualified arborist, with the offer of a job at the end for those who want one.

Get in touch to find out whether our training is the right fit for you.

Why Chainsaw Training is Essential for Safety

A chainsaw is one of the most powerful hand-held tools you will ever use. It can cut hardwood in seconds, which is exactly what makes it so useful and so dangerous. Every year in the UK, hundreds of chainsaw-related injuries are reported, and the majority of them happen to people who have had little or no formal training.

So why is chainsaw training essential for safety? Because knowing how to start the machine is not the same as knowing how to use it properly.

The Risks Are Real

Most chainsaw injuries involve the legs, hands, and arms. Kickback, where the guide bar is thrown back towards the operator, is one of the most common causes of serious accidents. It happens fast and without warning, usually when the nose of the bar catches on a branch or log. Without training, you simply will not know how to position yourself or the saw to reduce this risk.

Other frequent causes of injury include cutting under tension without recognising it, poor footing on uneven ground, and not wearing the correct protective equipment. These are all things that a good training course will address before you ever pick up the saw.

What Proper Chainsaw Training Covers

At DTE Academy, our City & Guilds NPTC Chainsaw Maintenance and Cross-Cutting course is built around two core units. The first focuses on understanding how the chainsaw works, including its components, maintenance requirements, and correct fuelling and chain sharpening. The second unit moves into practical cross-cutting technique, covering tension and compression, pivot points, body positioning, and safe working practices on site.

You will also learn how to carry out a proper risk assessment before starting any cut. This is not a box-ticking exercise. It is the single most important habit you can develop when working with chainsaws, whether commercially or on your own land.

It is Not Just for Professionals

A common misunderstanding is that chainsaw training is only for people looking to become tree surgeons. That is not the case. Farmers, estate workers, landowners, and conservation volunteers all benefit from knowing how to handle a chainsaw safely. If you are going to use one, you should know what you are doing.

Book Your Place

We run our chainsaw courses regularly at our base in Shoreham, Kent, with all equipment provided and meals included throughout the day. No previous experience is needed.

If you would like to find out more or check upcoming dates, get in touch with us today.

Educational Requirements to Become a Tree Surgeon

 If you’re someone who loves to go on adventures into the woods or has an immense appreciation for nature, becoming a tree surgeon or arborist has probably crossed your mind. Tree surgeons earn a living doing what they enjoy while helping protect the environment.

Apart from being personally rewarding, becoming a tree surgeon is also a practical career choice. According to the National Careers Service, there are thousands of job opportunities for tree surgeons throughout the UK, and job growth in this sector is likely to go up in the future.

To pursue a career as a tree surgeon, you need certain skills and specialized training. Read on to learn about the educational requirements for becoming a tree surgeon. 

Tree Surgeon Courses

To prepare you for the role of tree surgeon, you can:

Go to University

You can study for a foundation degree, a degree or a higher national diploma.

 Below are some of the courses you can take to become a tree surgeon:  

• Arboriculture

• Forestry

• Countryside Management

• Woodland Ecology and Conservation

You may only need 1 or 2 A levels or equivalent if you want to get a foundation degree or higher national diploma. But for a degree, you may be required to have 2 to 3 A levels. 

Take a College Course

A great way to fast-track your career is by taking college courses on the skills and knowledge that tree surgeons are required to have. Some examples are: 

• Level 2 Award in Tree Climbing and Aerial Rescue

• Level 2 Award in Felling and Processing Trees

• Level 2 Certificate in Arboriculture

Keep in mind that some companies and organisations that employ tree surgeons may have educational requirements different from what was discussed above.

Tree Surgeon Apprenticeship Program

There is really no set of academic qualifications needed to become a tree surgeon. You can also become one by signing up for an apprenticeship programme.

To qualify for an intermediate apprenticeship, you may need to have general certificates of secondary education (GCSEs), typically including English and Maths.

A good understanding of basic math is helpful for a tree surgeon, as they would often need to measure lengths and work out prices. You may also be required to take a diploma course in trees and timber during your placement.

Become a Qualified Tree Surgeon

You can gain work experience by volunteering in organisations like The Tree Council or National Trust. However, building your skills with tree surgeon training through DTE Academy is a simpler and faster way to start your career as a tree surgeon.

We offer practical training and forestry and arboricultural courses that will teach you all the skills you need as well as provide you with hands-on experience. Get in touch with us today to learn more about our courses.

Which Tree Surgery Qualifications Do I Need to Become a Tree Surgeon?

If you are thinking about a career in arboriculture, one of the first questions you will ask is: what qualifications do I actually need? It is a fair question, and the answer is more straightforward than you might expect.

The Core Qualifications Every Tree Surgeon Needs

Tree surgery is a hands-on profession, and your qualifications need to reflect that. At a minimum, you will need the following City & Guilds NPTC certificates to work as a professional tree surgeon in the UK:

Chainsaw Maintenance and Cross-Cutting is where most people start. This course covers how to look after your chainsaw, carry out pre-start checks, and perform cross-cutting operations safely. You cannot do any meaningful tree work without this qualification, so consider it your foundation.

Felling and Processing Trees up to 380mm builds on your chainsaw skills and teaches you how to fell small to medium-sized trees safely. You will learn about hinge formation, escape routes, and how to deal with hung-up trees.

Tree Climbing and Rescue is essential if you want to carry out aerial work, which makes up a large part of the job. This qualification proves you can climb safely using ropes and harnesses, and that you know how to rescue a colleague if something goes wrong at height.

Safe Use of a Manually Fed Wood Chipper rounds out the set. Clearing and processing waste is part of every job, and employers expect you to hold this certificate before operating a chipper on site.

Are There Any Other Qualifications Worth Having?

Once you have the core certificates, you can continue building your skills with additional qualifications in areas like aerial cutting, large tree felling, and the use of a mobile elevating work platform (MEWP). A first aid at work certificate is also strongly recommended, and many employers will ask for one before hiring.

The Fastest Way to Get Qualified

If you are starting from scratch and want to cover everything in one go, our DTE Academy Qualified Arborist Suite brings all of the essential qualifications together into a single six-week programme. It is the quickest and most practical route into the profession, and those who complete it successfully are offered the chance to start work with us straight away.

Do I Need a Degree or Previous Experience?

No. You do not need a degree, and none of our courses require previous experience with chainsaws or climbing. What you do need is a good level of physical fitness, a willingness to learn, and a genuine interest in working outdoors.

Ready to Get Started?

At DTE Academy, we have trained hundreds of people to begin careers in tree surgery. Our instructors are commercially experienced professionals who work in the field every day, not just in the classroom. If you want to know more about which qualifications are right for you, get in touch or browse our full list of courses.