Plant Protection

Course CodeBHT207
Fee CodeS2
Duration (approx)100 hours
QualificationStatement of Attainment



  • Sanitation - maintaining good hygiene
  • Physical control methods e.g. mowing, slashing, burning, flooding, hand removal, physical barriers (ie. netting, fences), etc.
  • Using plant varieties that are resistant to pests and diseases
  • Biological controls
  • Chemical controls (artificial and naturally derived).
  • Soil drenches/dips

This course takes a "wholistic approach, giving appropriate consideration to all of these "methods", without bias toward any particular method

Lesson Structure

There are 10 lessons in this course:

  1. Introduction - scientific names, terms, diagnosing problems.
  2. Control Techniques - natural & chemical.
  3. Chemicals - characteristics.
  4. Identifying Diseases - symptoms, fungi and viruses, and other pathogens.
  5. Disease Control - life cycle of fungi.
  6. Insect Classification and biology.
  7. Insect Control - how to control pests.
  8. Other Pests - nematodes, snails, millipedes.
  9. Weed Identification and chemical control.
  10. Non-chemical Weed Control

Each lesson culminates in an assignment which is submitted to the school, marked by the school's tutors and returned to you with any relevant suggestions, comments, and if necessary, extra reading.


  • Identify the broad category which a plant health problem belongs to.
  • Explain a range of methods for controlling plant problems.
  • Select appropriate chemical pesticides for different problems.
  • Identify the symptoms of different plant diseases, including most common and some uncommon problems, in your locality.
  • Develop procedures to control specific plant diseases.
  • Identify different insects, including significant taxonomic orders, common pest species, and some less common pest species
  • Determine appropriate methods to control different types of insects.
  • Identify different non-insect pests found in the learner's locality.
  • Determine appropriate control methods for different non-insect pests.
  • Identify different non-insect pests found in the learner's locality.
  • Determine appropriate control methods for different non-insect pests.
  • Manage the control of different types of weed problems.

How to Control Garden Pest and Disease

To control pest and diseases naturally there are four methods to consider:


1. Cultural Controls

  • the methods you use to grow plants


2. Physical Controls

  • methods which physically interfere with pests or diseases


3. Sprays or Dusts

  • natural products which control pests or diseases without having any undesirable side effects


4. Biological Controls

  • where other organisms control the pest or disease buy such means as
  • directly attacking the problem
  • by repelling it
  • or by attracting or luring pests to a place where they can be easily trapped or collected, and then easily destroyed or removed elsewhere


Here are some more tips for Plant Protection; but if you are really serious, you need to make a serious study of the subject through this course or something similar.




Choose the Right Plant for the Right Position

Growing your plants at the correct time of year in a position suited to them will reduce the likelihood of pest and disease problems occurring. Plants which are grown in the wrong circumstances will be stressed and prone to pest and disease problems.


Choose Healthy Plants

As a general rule, healthy plants will show greater resistance to pest and disease attack, and will be more likely to recover if they are attacked. When propagating your own plants make sure you only use propagating material from healthy vigorous parent plants. When buying plants make sure you only choose healthy looking ones. Carefully inspect the plant, the surface of the potting mix, the plant container, etc for signs of pest and disease infestations or other problems. When selecting bare rooted plants, such as fruit trees, carefully check the roots for signs of damage, abnormal swellings or growths, etc. A little time and care taken in the selection of your plants will usually mean a big reduction in pest and disease problems later on.


Choosing Resistant Varieties

Some plants seem to have few pest and disease problems. These plants are said to be resistant or tolerant. In some cases this is because pests and diseases are simply not attracted to that particular type of plant. In other cases the plant directly affects any insects or pests attempting to live on it, for example by exuding chemicals that repel the pest.

Some plants also have a greater ability to withstand insect or disease damage than others. In some cases the regular pruning back of foliage by insects can help to keep some plants vigorous. By choosing such resistant or tolerant plants you will reduce the likelihood of problems occurring.


Crop Rotation

Different crops will attract different pest and disease problems. It is always a good idea to grow crops on a rotation system, as growing plants of any kind in the same soil year after year can produce ideal growing conditions for certain types of pests and diseases. By changing the crops around, this prevents any such build up, as the plants that the pest & diseases grow on (the host plant) are constantly changed, and any such problems are not carried over from year to year to following crops. Crop rotation plays a vital role, in particular in controlling root diseases. A lot of crops will also have different nutritional needs; so again, rotation will prevent specific crop nutrients in the soil from becoming exhausted.


Timed Planting

Although it is not always possible, some crops can be grown at the time of year when populations of the pests or diseases that affect them are at their lowest. Cabbages and cauliflower, for example are less affected by the caterpillars of the cabbage white butterfly if they are grown through winter, avoiding warmer seasons when the butterfly is common. Growing crops early on in their normal growing season before pests and diseases have a chance to build up can also often help reduce pest and disease problems. In this case you can start your vegetables, flowers, etc off early, perhaps in a glasshouse or cold frame, so that they can be established outside as early as possible.



At harvest times, crops that have contact with the soil such as Strawberries, Marrows, Zucchinis (courgettes), are very susceptible to fungal diseases. Mulch can be laid under the plants so that the crop does not come into direct contact with the soil. This is usually a material, such as straw, which helps to keep the crop clean and dry, and therefore reduces the instances of fungal disease.


Cleanliness & Hygiene

If the area around your plants is kept clean and free of pests and disease there is less chance of your plants being affected.




  • Only bring clean soil into the garden.
  • Preferably work with the soil you have, but if you have to bring in soil from elsewhere be careful that you are not importing soil that is full of pests and diseases, weed seeds or other problems. When buying plants be careful that the soils and potting mixes that they are grown in don't have similar problems.
  • Where possible obtain your soil and plants from a reputable supplier.
  • Where possible don't leave plants affected by pests or diseases (or plant parts) near healthy plants.
  • Use clean, sharp tools when working with plants. Regularly dip or rub over tools such as secateurs, handsaws, knives, etc. with an antiseptic/disinfectant such as methylated spirits, Dettol, chlorine, etc. Keep cutting tools sharp to prevent tearing or ripping of plant material, which may make the plant more susceptible to attack.
  • Place pot plants on clean soil free surfaces (e.g. on concrete, paving or raised up on bricks). This prevents the spread of disease up into the pot from the soil.
  • Hang your hose on a hook, or wind it up; do not leave it lying on the ground where it is more likely to come in contact with pests and diseases i.e. fungal spores, which are then easily spread to your plants when you use your hose.
  • Place container plants suspected of pests or disease in an isolated place, until the problem has been treated.
  • Keep a close eye on plants ‑do something about problems immediately they are noticed.
  • Avoid having muddy areas...improve drainage. Have drains take excess water away from garden, not just redistribute it and any disease which might be in it.
  • Clear away any weeds which are near your crops and flowers. Many weeds will act as hosts to diseases and pests which affect your crops. Keep in mind that some pests, like aphids and leafhoppers, also spread viral and bacterial diseases as they suck sap and move from plant to plant.
  • Climate modification ...reduce pest or disease populations by creating environments they don't like, for example:
    1. improving ventilation will often help control fungal problems
    2. moving container plants to a hotter or cooler spot may deter different insects
    3. creating drier or damper conditions will often deter different pests, for example some ants don't like very moist soil, slugs thrive in damp areas but dislike dry places





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