Sustainable Pest Management to protect Biodiversity and Environment

4 Seeds in a hole, 1 for the Rook 1 for the Crow, 1 to Rot and 1 to Grow

Sustainable management of pests is seen as a way to deal with pests but we should try pest prevention first!

Preventing Pests

By far, the best way to protect your building or home is by integrating prevention techniques into your everyday practices. This is both a critical step and effective strategy when it comes to avoiding pests. Here are some prevention methods to practice:

  • Remove any sources of food, water or shelter that may attract pests.
  • Store items in safe and enclosed containers.
  • Dispose of garbage regularly with a tightly closed lid.
  • Reduce clutter or areas where pests can hide.
  • Seal and close off any cracks or holes to eliminate outside entry.
  • Perform checks regularly and keep your space clean.

Keep Your Soil Healthy - Healthy soil produces stronger plants that have better resistance to any damage incurred by insects. Before planting, turn over the soil and add organic matter such as manure or compost to supply essential nutrients.

Sustainable Options for Management of Pests in the Garden

There is a saying ‘If something is not eating your plants then your garden is not part of the ecosystem’. Therefore not everything is a pest and some things we should encourage and learn to live with. We are now in a Biodiversity Crisis it is time to change how we see garden pests. 

With biodiversity in crisis, perhaps we should focus on the good these creatures do in our gardens. But even the plant-nibbling slugs, snails and sap sucking apnhids can play a vital role in recycling dead plant material and animal waste, and acting as a food source for hedgehogs, frogs, birds, beetles and other insects. Our gardens would be a boring and alot messier without them.

A rose covered in a healthy population of greenfly would be a big problem from many gardeners,  we are constantly fighting to stop aphids from ruining a rose but how many have given a thought to the diversity, complex lifecycles and importance to ecosystems of these little insects? Can we start looking at the positives of these creatures and at least give them some places to live.

There are about 500 species of greenfly, blackfly and other aphids; some species are pink, others yellow. Forming dense colonies on many plants in spring, they are the basis for much life in the garden. They are eaten by a multitude of predators, including many of our beautiful ladybirds. Aphids support bird populations too. Watching wrens searching plants for aphids is such a lovely experience.

The RHS for example no longer view snails and slugs as pests. In instances where these creatures may cause unwanted damage to plants, more “ethical” modes of intervention should be used. 

1. Pests’ Natural Enemies
Not all insects are bad! Insects such as parasitic wasps, ladybirds, spiders and ground beetles are all beneficial to a garden as they prey on pests. Look out for these garden-friendly insects and try to encourage them into your garden by planting pollen and nectar producing plants, crop rotation, cover crops and organic matter..

2. Use Physical Barriers
Create a physical barrier to stop pests getting to your fruit and vegetables. There are a number of ways to do this but one of the easiest is to use a fine net. Position the net over your plants, leaving enough space for the plant to grow. Adding a cardboard collar around the stem of a plant and pressed into the soil an inch or so deep, will prevent cutworms and other burrowing insects from getting to your plants through the soil. You might also use a wool slug barrier pellets which are available in shops.  Wool fibres have very fine scales on them with tiny barbs which irritates the slugs preventing them going across the pellets.

3. Companion Planting
Some plants produce a natural insect repellent, which makes them very beneficial when planted next to crops, and this is known as companion planting. Roses deters aphids, Marigolds deter Whitefly, Spring onions, Leeks or Mint can deter Carrotfly. Nasturtiums can attract slugs, snails and whitefly away from Brassicas.

A water and Cider vineagar spray will remove woolly aphid from indoor plants.

Rabbits have a strong sense of smell, which they use to find accessible food sources. You can take advantage of this trait by using scents they dislike, such as garlic, vinegar, chili powder, chives, lavender, geraniums, and wax begonias.

5. Hand Pick Larger Pests

Hand picking larger pests such as slugs can be quite efficient, especially in a small garden. If you’re feeling squeamish, wear a pair of gardening gloves and gently move them away from the area where they are unwanted.

6. Use non chemical control for weeds or just leave the weeds be!

Hoeing is a good alternative to chemicals, pull deep rooted weeds or use physical barriers such as mulch can be very effective and improve your soil. If you can just leave the weeds be!

What is Driving the move away from Chemicals for Weed Control?

In recent years, a growing body of evidence has pointed to the hazardous properties of glyphosate and other herbicides, the risk their use poses to the user and the public as well as wider concerns about the potential for herbicides’ negative effects on biodiversity.

Several other countries have already taken action to stop and reduce the use of herbicides, most notably in France where a ban on the use and sale of non-agricultural pesticides has been in place since January 2019. Both Germany and Austria have announced intentions to end the use of glyphosate in the next few years. Many European rail companies are also investigating the use of alternatives to glyphosate for track maintenance.
Dún Laoghaire Rathdown County Council are also leading on eliminating the use of chemicals for weed control across its parks, open spaces, roads etc.
There are many and varied benefits to switching to a non-chemical weed control approach:

  • Environment: reduced pollution (air, ground and water).
  • Herbicide use: in urban areas, and more specifically on impermeable surfaces, is a source of water pollution which generates significant costs for water companies and subsequently to the end user.
  • Biodiversity: benefits to pollinating insects and other beneficial insects, soil micro-organisms, birds, amphibians and plant diversity.  Citizens: protection for the most vulnerable groups from exposure to potentially harmful substances thus improving the quality of life for residents (and their pets) and those entering the city and its green areas.
  • Health: will be better protected from the short- and long-term health consequences of occupational exposure to herbicides.
  • Reducing your costs: adoption of pesticide free techniques has shown cost savings in the long-term
  • Legal and financial liability: reduce or remove the potential for an expensive court case taken by operators or bystanders who develop health problems resulting from exposure to herbicides

For more information and to find out more about alternatives to using chemicals for weed control, please click here

How to control weeds without chemicals

Ask yourself do you really need to remove the plant in the first place, can you accept some of those plants that are valuable for pollinators and insects and let them be such as dandelions?
If you cannot, then here are some non chemical ways of doing it from the RHS. Click here for more info.

1. Manual removal and cutting back

Hoeing: Run a hoe over a bed or between rows to kill most weed seedlings. For maximum effectiveness, choose a dry day with a light wind, so that the seedlings will dry out on the surface of the bed rather than re-rooting into moist soil
Hand-pulling or hand-weeding with a fork: Pull up annual weeds by hand before they set seed. Perennial weeds should be dug out with as much root (or bulb) as possible, using a hand or border fork. Hand weeding is easiest on lighter soils and should only be attempted where it will not disturb the roots of garden plants. Further pulling may be necessary with persistent weeds such as bindweed or couch grass where small root sections left behind can re-grow into new plantsWeed knife and other weeding tools: A weed knife has a hooked end and is a useful tool for weeding between paving slabs and along path edging. Various other hooked, narrow-bladed or spiral-type tools are available for specific weeding jobs such as digging out dandelions on a lawn
Repeated cutting: In large weedy areas, repeated cutting to ground level over several years will weaken and even kill some weeds. This is usually done with a strimmer or sickle-type weeder
Flame gun: Scorch off weeds between paving slabs and on driveways by blasting them with a flame gun. Use only when the foliage is dry and allow sufficient burn-time for deep-rooted weeds, such as dandelions, to be killed.

2. Weed barriers

Mulching: Use deep organic mulches such as bark or wood chip to smother weeds around plants. To be effective, keep them topped up to a minimum depth of 10-15cm (4-6in) to smother established annual weeds. Keep woody stems clear of mulch to prevent rotting
Edging boards or strips: These can be used to edge lawns and grass paths to prevent unwanted grass growth into the border. Especially useful where invasive rooted grasses such as couch grass are a problem
Root barriers: These can be inserted into the soil to stop the spread of perennial weeds such as ground elder and horsetail into neighbouring areas or gardens. They can also be used to restrict invasive plants such as bamboos, or suckering trees, shrubs and raspberries. A straight barrier can be formed from paving slabs or corrugated iron sheets, but for a flexible solution use a tough fabric root barrier.

3. Weed-suppressant fabrics

Groundcover or landscaping fabrics can be laid over recently cleared soil to suppress re-growth of old weeds and prevent new weeds from establishing.
There are a number of different weed suppressant fabrics available, each with its own advantages and disadvantages. Brown cardboard covered in woodchip is also effective. 

Don't Risk It!

New EU legislation in relation to plant health is now in force and there are new stricter measures to control the entry and spread of pests and diseases of plants in particular personal consignments on individuals when travelling. An outbreak of these pests and diseases can cause significant damage to the environment, the horticulture industry, public parks, private gardens and have serious economic consequences on people’s livelihoods.

The Department of Agriculture, Food & the Marine are promoting a “Don’t Risk it!” awareness raising campaign targeted at travellers, tourists and commercial businesses who are bringing plants, plant products and other high risk items made of plant material into Ireland from abroad.

More information can be found here.

Rodent Control

Rats communicate and mark their territory by urinating everywhere they go, representing a significant public health risk. They can carry many nasty diseases, which can spread to humans, normally through rats’ urine or body coming into contact with food preparation areas.
These include:
• Leptospirosis (often referred to as Weil's disease)
• Salmonella
• Listeria
• Toxoplasma gondii
• Hantavirus

Some ways of discouraging rats include:

1. Remove access to food – get rid of whatever they are eating or prevent their access to it (e.g. by rat-proofing buildings). Change feeder designs, feeder positions, and feeding regimes so that the birds/animals you want to feed can access the food but rats cannot or are more exposed to predation. In urban areas, taking in bird feed at dusk is a way to remove an easy food supply during normal feeding time.
2. Cover any household waste where rats can get access to it and close dustbin lids. Recycling containers should also be washed to remove any food residue.
3. Remove harbourage – remove whatever the rodents are under, in, or behind. Block holes with stone, cement/concrete, ferrous metal or balls of squashed wire netting. Note: following MAFF-funded research, the Central Science Laboratory reported that removing harbourage is as effective as using poison and more useful as a long term approach (Lambert et. al 2003).
4. Ensure that drain inspection covers are in a good state of repair and any disused pipes are sealed off.
5. Encourage natural predators – Be tolerant of Foxes – they also eat rat.

6. Keep rat burrow areas clear of vegetation.

However, always seek advice from a pest control company with experience in professional rat control where you suspect the presence of rats and contact DLR or the HSE where relevant.  The responsibility for keeping land or premises free from rats or mice lies with the occupier. EHOs have legal powers to deal with premises infested with rats or mice. If the rat or mouse issue is caused by accumulations of waste or litter or occurs on public land please contact your Local Authority. If the infestation is associated with drains or sewers please contact Irish Water at

dlr does not recommend that you try to manage rats without seeking professional advice from a pest control company, due to the serious Health and Safety concerns regarding rodents.

Further Information and reporting on rodent issues

For further information on rodents, visit the HSE website here or contact dlr at:

Infrastructure & Climate Change Department, County Hall, Marine Road, Dún Laoghaire

Phone: 01 205 4700


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