ntpw:natural_pest_and_weed_control

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ntpw:natural_pest_and_weed_control [2026/03/13 14:21] – [Related topics] Katja Durranintpw:natural_pest_and_weed_control [2026/06/07 15:36] (current) – [Controlling pests] Otto Hague
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-# Natural pest & weed control+This topic is part of [[gt:gardening|Gardening, smallholding & farming]]. 
 +====== Natural pest & weed control ======
  
  
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-## What is natural pest & weed control?+===== What is natural pest & weed control? =====
  
 Natural pest and weed control means using non-synthetic methods to prevent or kill weeds and pests in the garden. For example, instead of using glyphosate weedkiller ('Roundup') to tame an overgrown allotment, you could cover the soil with cardboard and straw for a few months. Or instead of spraying fruit trees to kill aphids, you could put up bird boxes in or near them and let the birds do the work for you. Natural pest and weed control means using non-synthetic methods to prevent or kill weeds and pests in the garden. For example, instead of using glyphosate weedkiller ('Roundup') to tame an overgrown allotment, you could cover the soil with cardboard and straw for a few months. Or instead of spraying fruit trees to kill aphids, you could put up bird boxes in or near them and let the birds do the work for you.
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-## What are the benefits of natural pest & weed control?+===== What are the benefits of natural pest & weed control? =====
  
 - Synthetic pesticides and weedkillers are poisonous, and therefore risky things to have around our homes, gardens and farms. - Synthetic pesticides and weedkillers are poisonous, and therefore risky things to have around our homes, gardens and farms.
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-## What can I do?+===== What can I do? =====
  
 Here's some more reading - from the [Henry Doubleday Association (now Garden Organic)](https://cms.lowimpact.org/wp-content/uploads/pests-doubleday.pdf) and from [South Carolina State](https://cms.lowimpact.org/wp-content/uploads/sg_part4.pdf) in the US. Here's some more reading - from the [Henry Doubleday Association (now Garden Organic)](https://cms.lowimpact.org/wp-content/uploads/pests-doubleday.pdf) and from [South Carolina State](https://cms.lowimpact.org/wp-content/uploads/sg_part4.pdf) in the US.
  
-### Controlling pests+==== Controlling pests ====
  
-First, make sure you are practising good [soil management](/soil/soil), because vigourous, healthy plants growing in healthy, well-managed soil are much less susceptible to pests.+First, make sure you are practising good [soil management](/soil/soil), because vigourous, healthy plants growing in healthy, well-managed soil are much less susceptible to pests. 
  
-**Encouraging pest predators**+Secondly, make a habit of walking your garden, fields, orchards, or other places you maintain. Take a good look at what is showing up, where, and when. Pests have different preferences and life cycles, and to most effectively prevent or clean up a pest problem you need to target them at their weakest. Their life cycles will also vary based on weather: most insects mature faster if it's warmer than usual. 
 + 
 +=== Encouraging pest predators ===
  
 Birds eat aphids, caterpillars and other insect pests, so one of the best things that you can do to reduce pests in your garden is to invite more birds into it. You can do that by giving birds places to live in your garden, and bribing them to visit and stay by providing food. You can buy or make bird boxes. Designs vary depending on which type of bird you want, e.g. robin boxes have a letter-box shaped slot at the front, and blue-tit boxes have a small hole for an entrance. You can easily find instructions and plans for bird boxes online. Now, think about your bird menu - you could plant trees and bushes with berries that attract birds, such as hawthorn and rose hips, or flowers that produce seeds that birds enjoy, such as sunflowers, zinnias, cornflowers and marigolds. Be careful though not to attract birds towards the berries that you want to harvest, such as your soft fruit area – best to attract the birds towards the vegetable beds and fruit trees. Birds eat aphids, caterpillars and other insect pests, so one of the best things that you can do to reduce pests in your garden is to invite more birds into it. You can do that by giving birds places to live in your garden, and bribing them to visit and stay by providing food. You can buy or make bird boxes. Designs vary depending on which type of bird you want, e.g. robin boxes have a letter-box shaped slot at the front, and blue-tit boxes have a small hole for an entrance. You can easily find instructions and plans for bird boxes online. Now, think about your bird menu - you could plant trees and bushes with berries that attract birds, such as hawthorn and rose hips, or flowers that produce seeds that birds enjoy, such as sunflowers, zinnias, cornflowers and marigolds. Be careful though not to attract birds towards the berries that you want to harvest, such as your soft fruit area – best to attract the birds towards the vegetable beds and fruit trees.
 +
 +If birds end up becoming a problem, you can put up perches or nest boxes suitable for raptors like buzzards. Raptors will take care of birds and rodents, and make those that survive much less bold.
  
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 Frogs and toads eat lots of slugs, so it's a great idea to have a wildlife pond in or near your food-growing area. The pond doesn't need to be all that big – even an old bucket or sink buried in the ground would do – just be sure to make ramps for wildlife to get in and out. Hedgehogs are also useful predators of slugs, snails and caterpillars, so make your garden hedgehog-friendly by having an area of long grass or other cover, removing barriers and accidental traps, and if you feed them, check what they should eat (i.e. not bread and milk); more details [here](https://www.rspb.org.uk/birds-and-wildlife/advice/gardening-for-wildlife/homes-for-hedgehogs/). Frogs and toads eat lots of slugs, so it's a great idea to have a wildlife pond in or near your food-growing area. The pond doesn't need to be all that big – even an old bucket or sink buried in the ground would do – just be sure to make ramps for wildlife to get in and out. Hedgehogs are also useful predators of slugs, snails and caterpillars, so make your garden hedgehog-friendly by having an area of long grass or other cover, removing barriers and accidental traps, and if you feed them, check what they should eat (i.e. not bread and milk); more details [here](https://www.rspb.org.uk/birds-and-wildlife/advice/gardening-for-wildlife/homes-for-hedgehogs/).
  
-You can also reduce pests in your garden by encouraging beneficial insects. Almost everyone knows that ladybirds eat huge quantities of aphids (especially at the larval stage – see photo). Lacewings also eat aphids and are to be encouraged. There are two main things you can do to encourage beneficial insects: firstly, never use pesticides, as pesticides wipe out your beneficial insect population (i.e. the opposite of encouraging them). Since pests such as aphids reproduce faster than beneficial insects, all you do is make the problem worse and end up in a vicious spiral of ever-increasing pesticide use. Nasty! Secondly, you can make homes for your beneficial insects, by making a bug hotel. These can be made really easily and cheaply, for example just by cutting the end off a plastic bottle and filling it with dry hollow stems and sticks, or rolled up corrugated cardboard, then fixing it to a sheltered wall or fence. More information [here](https://www.rspb.org.uk/birds-and-wildlife/advice/gardening-for-wildlife/insects-and-minibeasts/).+You can also reduce pests in your garden by encouraging beneficial insects. Almost everyone knows that ladybirds eat huge quantities of aphids (especially at the larval stage – see photo). Lacewings also eat aphids and are to be encouraged. There are two main things you can do to encourage beneficial insects: firstly, never use pesticides, as pesticides wipe out your beneficial insect population (i.e. the opposite of encouraging them). Since pests such as aphids reproduce faster than beneficial insects, all you do is make the problem worse and end up in a vicious spiral of ever-increasing pesticide use. Nasty!  
 + 
 +Secondly, you can make homes for your beneficial insects, by making a bug hotel. These can be made really easily and cheaply, for example just by cutting the end off a plastic bottle and filling it with dry hollow stems and sticks, or rolled up corrugated cardboard, then fixing it to a sheltered wall or fence. More information [here](https://www.rspb.org.uk/birds-and-wildlife/advice/gardening-for-wildlife/insects-and-minibeasts/). Even more simply, you can leave stacks of brush, sticks, and/or rocks. Putting larger objects on the bottom of the pile will create lots of hiding places, which can attract insects (as well as hedgehogs and rodents).
  
 Another great tip to get lacewings breeding – leave a stack of the egg-holding parts of egg boxes on a shelf in your greenhouse or shed over the winter. Lacewings just love the spaces between the different layers, and in spring it will be full of new lacewings hatching out (leave it undisturbed from late summer until late spring). Another great tip to get lacewings breeding – leave a stack of the egg-holding parts of egg boxes on a shelf in your greenhouse or shed over the winter. Lacewings just love the spaces between the different layers, and in spring it will be full of new lacewings hatching out (leave it undisturbed from late summer until late spring).
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 In recent years it has become possible to buy insects such as ladybirds by mail order. This might be worth doing if you have plenty of money, a large greenhouse, a major aphid problem, and no ladybirds - but it's an expensive solution and the ladybirds might fly off elsewhere! You'll also often see adverts (if you read gardening magazines) for mail-order nematodes - tiny parasitic worms, less than 1mm long, which get into slugs and kill and eat them from the inside (yuk). These are watered into the soil starting in early spring, and will control slugs for about 6 weeks, after which you might need to buy another pack - see [nemaslug.co.uk](http://nemaslug.co.uk). While some gardeners do find nematodes useful, longer term, rather than relying on a predator which you have to keep on buying all the time, you're probably better off taking other natural measures to control slugs - such as encouraging birds, amphibians and hedgehogs, and of course removing slug and snail habitats such as piles of stones and long grass around the edges of beds. In recent years it has become possible to buy insects such as ladybirds by mail order. This might be worth doing if you have plenty of money, a large greenhouse, a major aphid problem, and no ladybirds - but it's an expensive solution and the ladybirds might fly off elsewhere! You'll also often see adverts (if you read gardening magazines) for mail-order nematodes - tiny parasitic worms, less than 1mm long, which get into slugs and kill and eat them from the inside (yuk). These are watered into the soil starting in early spring, and will control slugs for about 6 weeks, after which you might need to buy another pack - see [nemaslug.co.uk](http://nemaslug.co.uk). While some gardeners do find nematodes useful, longer term, rather than relying on a predator which you have to keep on buying all the time, you're probably better off taking other natural measures to control slugs - such as encouraging birds, amphibians and hedgehogs, and of course removing slug and snail habitats such as piles of stones and long grass around the edges of beds.
  
-**Trapping**+If you're having a problem with a particular pest (it is super important to know what pests you're dealing with; spend time in your garden!) you can try and attract parasitoid wasps. These tiny wasps are super specialists, laying their eggs on or in only one or two species. When the eggs hatch, the wasp larvae feed off of and ultimately consume the host. Since the wasps are so specialised, they can take on problem pests like the cabbage aphid (*Brevicoryne brassicae*) which has a nasty habit of exploding and covering its predators in "mustard gas", killing ladybirds. Adult parasitoid wasps feed on nectar from flowers, so encourage them to move in naturally with lots of flowers, ensuring you have flowers that //bloom at different times of the year// so the wasps always have food. 
 + 
 +=== Trapping ===
  
 The best-known trap for slugs and snails is a 'beer trap'. Just fill a shallow dish with leftover beer, place it on the ground, and if the weather is wet, improvise a lid or cover which keeps out rain but allows in slugs and snails. They are attracted to the beer, climb into the trap, and drink themselves to death. You can also buy special plastic containers to use as beer traps, though making your own is simple and cheaper. Any container which can hold 2cm of beer, keeps out rain, but allows in slugs will do. The best-known trap for slugs and snails is a 'beer trap'. Just fill a shallow dish with leftover beer, place it on the ground, and if the weather is wet, improvise a lid or cover which keeps out rain but allows in slugs and snails. They are attracted to the beer, climb into the trap, and drink themselves to death. You can also buy special plastic containers to use as beer traps, though making your own is simple and cheaper. Any container which can hold 2cm of beer, keeps out rain, but allows in slugs will do.
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 You can also buy pheromone traps which you can hang in fruit trees to control pests, but this is usually only done by commercial fruit growers, who might for example use a pheremone trap to catch male codling moths in apple trees to reduce the number of maggoty apples in their crop. There are also sticky 'fly paper' traps which you can hang in plants in greenhouses to catch aphids. If you want to try these, be sure to only buy traps which don't contain an insecticide. You can also buy pheromone traps which you can hang in fruit trees to control pests, but this is usually only done by commercial fruit growers, who might for example use a pheremone trap to catch male codling moths in apple trees to reduce the number of maggoty apples in their crop. There are also sticky 'fly paper' traps which you can hang in plants in greenhouses to catch aphids. If you want to try these, be sure to only buy traps which don't contain an insecticide.
  
-Traps don't have to be lethal: you can provide shelters that slugs and snails will love to hide under – half an orange or grapefruit skin that's been squeezed for juice, placed skin side upwards to make a sort of igloo, is an old favourite, but a plank of wood laid on the soil will also do. Every morning, lift the traps and (with gardening gloves on) pick up the slugs and dispose of them either humanely or not so humanely (see below).+Traps don't have to be lethal: you can provide shelters that slugs and snails will love to hide under – half an orange or grapefruit skin that's been squeezed for juice, placed skin side upwards to make a sort of igloo, is an old favourite, but a plank of wood laid on the soil will also do. Every morning, lift the traps and (with gardening gloves on) pick up the slugs and dispose of them either humanely or not so humanely (see below). Shelter can also be used against other pests, like weevils, which naturally gravitate towards narrow spaces. Simply supply a narrow space, let the weevils gather inside, and then remove the shelter.
  
 Aphids love nettles, and so do ladybirds. One market garden grows nettles in pots, and places them near crops that they want to protect - newly arrived aphids then settle on the nettles and get eaten by the ladybirds. Aphids love nettles, and so do ladybirds. One market garden grows nettles in pots, and places them near crops that they want to protect - newly arrived aphids then settle on the nettles and get eaten by the ladybirds.
  
-**Hunting**+=== Hunting ===
  
 Slugs and snails are most active at night, so many organic gardeners who want to control their slugs and snails go out on 'slug patrol' with a torch and a bucket after dark to pick up the pests. Some hunters drown their prey in a bucket of water, but kinder souls keep a lid on the bucket them empty it a long way from their garden the next day. Slugs and snails are most active at night, so many organic gardeners who want to control their slugs and snails go out on 'slug patrol' with a torch and a bucket after dark to pick up the pests. Some hunters drown their prey in a bucket of water, but kinder souls keep a lid on the bucket them empty it a long way from their garden the next day.
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-In daytime, you can inspect your crops for pests such as caterpillars and aphids (blackfly, greenfly, whitefly). Caterpillars can be picked off and taken away or killed; aphids really just have to be squished between your fingers (or sprayed with a dilute household soap solution, which kills them and is safe and environmentally friendly). Garlic and chilli pepper solutions may also be useful as a natural insecticide.+In daytime, you can inspect your crops for pests such as caterpillars and aphids (blackfly, greenfly, whitefly). Caterpillars can be picked off and taken away or killed; aphids really just have to be squished between your fingers (or sprayed with a dilute household soap solution, which kills them and is safe and environmentally friendly). Garlic and chilli pepper solutions may also be useful as a natural insecticide. You can also spread vegetable oil on the walls of barns, which can suffocate fly larvae and eggs.
  
-**Barriers**+=== Barriers ===
  
 As well as a way of killing slugs, water also makes a very effective barrier that they won't cross. Now you probably can't construct your veg beds with a moat around them, but you can stand a pot or container on an upturned plant saucer, inside a larger plant saucer or shallow container that you fill with water. Voila - you've made a slug moat around your special plant. You can also stand the legs of plant tables or greenhouse staging in containers of water to prevent slugs from climbing up them. Making plant tables with legs of rough-sawn wood can also be pretty effective at stopping slimy visitors from climbing up them. As well as a way of killing slugs, water also makes a very effective barrier that they won't cross. Now you probably can't construct your veg beds with a moat around them, but you can stand a pot or container on an upturned plant saucer, inside a larger plant saucer or shallow container that you fill with water. Voila - you've made a slug moat around your special plant. You can also stand the legs of plant tables or greenhouse staging in containers of water to prevent slugs from climbing up them. Making plant tables with legs of rough-sawn wood can also be pretty effective at stopping slimy visitors from climbing up them.
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-**Confusion and disguise**+=== Confusion and disguise ===
  
 Some pests find the plants that they like to eat by sight – colour or shape – so it can be better to avoid the usual practice of planting blocks or rows of the same type of plant. Instead, plant mixtures of different types of plant in each area - growing 'polycultures' as some gardeners put it, but note that sweetcorn must be planted in blocks, to enable it to pollinate. Similarly, some pests use their sense of smell to find your crops, so some organic gardeners like to plant onions next to carrots, or French marigolds next to tomatoes, to try to disguise the smell of the crops. Some pests find the plants that they like to eat by sight – colour or shape – so it can be better to avoid the usual practice of planting blocks or rows of the same type of plant. Instead, plant mixtures of different types of plant in each area - growing 'polycultures' as some gardeners put it, but note that sweetcorn must be planted in blocks, to enable it to pollinate. Similarly, some pests use their sense of smell to find your crops, so some organic gardeners like to plant onions next to carrots, or French marigolds next to tomatoes, to try to disguise the smell of the crops.
  
-And finally, you can make a scarecrow or hang old CDs near to your baby brassicas to scare off pigeons.+And finally, you can make a scarecrow or hang old CDs near to your baby brassicas to scare off pigeons. Tools such as this need to be changed regularly, as bird can get used to them over time.
  
-### Controlling weeds+=== Cleanliness === 
 + 
 +Pest problems can be prevented or combated with good hygiene. A lot of insect pests need moist shelter that protects them from the extremes of heat and cold, and many require mud or manure. Keep water storage on impermeable surfaces so spillage doesn't result in a permanent mud puddle. If manure-dwellers are a problem, clean it up by chopping manure manually or letting chickens pick it over.  
 + 
 +Rodents require shelter, especially if there are predators in the area. Keeping groundcover short next to crops or young trees can discourage rodents, as they will have to cross an exposed area to get to your plants. During winter, you can pull back mulch from the base of young trees and other perennials. 
 + 
 +=== Rotation === 
 + 
 +Rotating crops and livestock can prevent a pest problem. Often, pests and diseases will stay in the soil over the winter, so if you plant the same crop in the same field, the pests will stick around. If you plant something different (and not closely related), the pests will have nowhere to go and may die off. The same goes for livestock parasites, which often spread via infected manure being left on pasture. Don't put the same kind of livestock in the same pasture for at least a year if you're worried about parasites. 
 + 
 +==== Controlling weeds ====
  
 There are plenty of better, safer alternatives to using synthetic weedkillers. There are plenty of better, safer alternatives to using synthetic weedkillers.
  
-**Mulching**+=== Mulching ===
  
 Mulching means putting a layer of material over the soil to exclude light, without which weeds won't germinate or grow. Mulching also benefits plants by keeping the soil most, reducing the need to water crops, and mulches (apart from black plastic) also eventually break down to produce soil-enriching compost. Mulching means putting a layer of material over the soil to exclude light, without which weeds won't germinate or grow. Mulching also benefits plants by keeping the soil most, reducing the need to water crops, and mulches (apart from black plastic) also eventually break down to produce soil-enriching compost.
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-**No-dig**+=== No-dig ===
  
 There are several reasons not to dig vegetable beds, and one of them is that digging continually brings to the surface a new flush of weed seeds, which can lie dormant in the soil for many years. Young weeds can be dealt with by hoeing, and sometimes using a sharp digging spade like a wide hoe to cut the weed tops from their roots can be a very quick and effective way to tidy up a bed between crops. There are several reasons not to dig vegetable beds, and one of them is that digging continually brings to the surface a new flush of weed seeds, which can lie dormant in the soil for many years. Young weeds can be dealt with by hoeing, and sometimes using a sharp digging spade like a wide hoe to cut the weed tops from their roots can be a very quick and effective way to tidy up a bed between crops.
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-**Prevention is better than cure**+=== Pigs === 
 + 
 +If you have [pigs](https://knowledge.growingthecommons.org/doku.php/pigs/pigs), they are good at controlling weeds. Once it's autumn and pigs have fewer plants above ground to forage, they will begin to dig up the tubers of plants to eat. They are very effective at digging up weeds that regrow from taproots and rhizomes, such as bracken.  
 + 
 +=== Prevention is better than cure ===
  
 If you can, avoid ever letting weeds set seed. Hoe or mow down weeds before they flower. This 'stitch in time' policy will hugely reduce the amount of weeding required, though some weed seeds will always blow in from elsewhere, especially on an allotment site where some plotholders are less careful. If you can, avoid ever letting weeds set seed. Hoe or mow down weeds before they flower. This 'stitch in time' policy will hugely reduce the amount of weeding required, though some weed seeds will always blow in from elsewhere, especially on an allotment site where some plotholders are less careful.
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-## Further resources+===== Forum ===== 
 + 
 +This topic belongs to the section [[gt:gardening|Gardening, smallholding & farming]]. You can ask questions or add information on the corresponding [Forum section](https://forum.growingthecommons.org/t/gardening). 
 + 
 +===== Further resources =====
  
 - [Naturally repelling slugs](http://lowimpactorg.onyx-sites.io/posts/stop-slugs-allotment-garden-naturally) - [Naturally repelling slugs](http://lowimpactorg.onyx-sites.io/posts/stop-slugs-allotment-garden-naturally)
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-## Related topics+===== Related topics =====
  
 - [[nuts:nuts|Nuts & nut trees]] - [[nuts:nuts|Nuts & nut trees]]
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-## Specialist curators of this topic+===== Specialist curators of this topic =====
  
 +[Otto Hague](https://knowledge.growingthecommons.org/doku.php/user/osedax)
  
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  • Last modified: 2026/03/13 14:21
  • by Katja Durrani