Many gardeners are becoming increasingly worried about the short and long-term effects of the agricultural chemical herbicides used to control pests food crops. Many respected scientists have linked certain cancers and other diseases to the use of non-organic herbicides. We have also witnessed a huge decline in insect populations, many of which (ironically) are pest controlling predators.
What can we do as keen, organic gardeners? Firstly, we need to cut down or even better, cut out the use of chemicals in the garden. I know that the easy option is to use cheap-as-chips slug pellets and to spray prized veg with insecticide. However, by doing so we are making things worse. By removing the natural pest controls (beneficial insects) that inhabit our gardens, we are only making the situation worst and unsustainable.
So, it’s all doom and gloom then? No, of course not! Here are some and organic, Natural pesticides for the vegetable garden and herbicides to protect your plants:
Natural herbicide treatments
- Fire: Reducing weeds to ashes is a sure-fire way of getting them out of your life. Any direct heat on foliage will cause the weeds to wilt. Repeated application will results in the eventual death of the weed. Use a flame-weeder tool with great care, especially in dry weather! You don’t want to set fire to your neighbourhood.
- Borax: You can still buy this online as a cleaning product and makes a great herbicide. Add 20 ounces of borax (powder) to 5 gallons of water. After mixing apply to the leaves of the weed with a sprayer.
- Vinegar: White vinegar can be purchase in just about any supermarket. It usually contains about 5% acetic acid, which is enough to inflict harm on most weeds. Spray, undiluted onto leaves. Add a couple of drops of washing up liquid for a great effect. Repeat until the weed gives up! Try not to breath in the vapour as this will result in irritation.
- Salt & vinegar: You can also dispatch weeds with a mixture of sea salt and white vinegar. Mix 1 gallon of vinegar to 1 cup of salt. Spray the undiluted mixture directly onto the leaves and repeat until the weed is dead. Again, a few drops of washing up liquid will make the mixture more effective.
- Sork bulbs: An entirely natural solution to prevent mole damage to lawns and flower/vegetable beds. Once planted in the earth the bulbs release a smell undetectable to humans but highly offensive to moles and field mice. They will continue to ward off moles for up to 2 years. Plant each bulb 8 metres apart and at a depth of between 5 – 8 cm.
Aphids are one of the most common pests in gardens during the summer months. They extract valuable plant sap and deposit honeydew on green growth. This, in turn often leads to fungal infections and other diseases. Both blackfly and greenfly are prolific reproducers. They can inflict serious damage in a very short period and encourage the spread plant viruses to the infested plants and other specimens.
- Predatory aphid control: There are many natural predators which can solve this issue. Hoverflies, Ladybirds and Lacewings will readily feed on aphids. You can buy Hoverfly and Lacewings larvae online or from some garden centres. Failing that, you could also try to encourage these beneficial insects into your garden by installing habitats for them. The registered charity www.buglife.org has plenty of information and instruction on constructing ‘bug hotels’. Bug hotels also provide a fascinating study for children of all ages.
- Soapy water aphid control: Another highly effective method for aphid control is to spray your plants with soapy water. Use a teaspoon of eco-friendly washing-up liquid diluted in 3 litres of cold water. I prefer to shake the mix to produce a foam. This will help drench the infected areas. Aphids breathe through their skin and soapy water inhibits this ability and quickly suffocate. If you are using this method, please be careful not to inadvertently spray beneficial insects. Also, don’t over do it with the washing up liquid. Too strong a mix may damage your plants. You may have to experiment with mixtures with different brands of washing up liquid.
Chafer grub killer
Chafer Beetle grubs, if they are left untreated, can inflict severe damage to lawns. The grubs overwinter deep in the soil ready to cause more damage the following spring. Lawns develop yellow patches where the roots have been eaten by the grubs of the Chafer Beetles. In severe cases, the roots are completely destroyed and the turf can be pulled up easily. Further damage may occur from birds and other animals as they ransack lawns looking for the grubs to eat.
During early summer, Chafer Beetles lay their eggs, deep within the turf. The eggs then develop into the dreaded Chafer grub. When fully grown, these grubs can cause carnage from Autumn to Spring. They are easily identified by their brown heads and white bodies. Chafer grubs can usually be found from early August.
- Nematode Phasmarhabditis hermaphrodita: One of the best treatments for an infection of Chafer grubs is the introduction of tiny nematodes as soon as the grubs appear in August. Water the Nematodes into an aerated lawn.
As small as they are, ants can rapidly ruin lawns, undermine plants and invade your home. There are many methods of organic control to try:
- Lemon juice: Spray around the opening to the ant mound with pure, undiluted lemon juice. The acid in the juice somehow confuses the ants and disrupts their activities.
- Cinnamon powder sprinkled directly or as an essential oil mixed with water and sprayed. Ants hate cinnamon. Cinnamon also makes your home and garden smell nice.
- Borax and sugar: Mix equal parts of these ingredients with water into a paste and spread into a plastic lid. The ants will carry off small quantities of this poisonous mixture back to their nests. Ensure that your pets or small children don’t encounter the mix as it is poisonous.
- Baking and sugar: This should be applied and works in the same way as Borax and sugar, with the added benefit of being not toxic to humans or animals.
- Peppermint oil: Another essential oil hated by ants. They will not go near the stuff and abandon nests if sprinkled nearby.
- Chalk: Not sure how useful this will be, but ants don’t like crossing lines of chalk!
Caterpillars hungrily feed on the leaves of many flowers and vegetables. Their massive appetites can result in monumental damage in the garden.The more they eat, the larger they grow. The larger the grow, the more they eat!
- Squash eggs before they hatch: This method requires vigilance. As soon as you see butterflies in your garden, you need to start checking the underside of the leaves of your vulnerable plants for eggs. They often appear as small yellow or white dots, laid out in well-ordered lines. Squash them between your fingers being careful not to damage the leaves.
- Handpicking: By far the best method for caterpillar control is to do things manually. Handpicking is an effective way to stop them before they ruin your plants. However, it can be difficult to spot the younger caterpillar hatchlings as they are often very small. You can either ‘squash’ them or place them in a bucket of soapy water.
- Bacillus thuringiensis: Dust leaves with the powdered form of this natural bacteria that eradicates caterpillars. This agent has the added benefit of not being harmful to most other beneficial insects.
- Birds: Encouraging birds into your garden is right on so many levels. By no means least of these benefits is natural pest control. There are so many insects that birds like to eat. Put different types of feed into bird tables and ground trays to encourage them into your garden. It may take a little persiverance, but will pay off in the end.
- Crop rotation: Don’t plant the same plants in the same spot for more than one year running. This will not only keep the caterpillar populations down but also help lower the risk of plant diseases and infections.
Eliminating Red Spider Mite
Red Spider Mites attack conservatory plant and vegetable crops, including peppers, aubergines and cucumbers. They will rapidly weaken an infested plant. This will quite often result in the death of the plant as other infections can easily get a foot-hold. Red Spider Mites are hard to eradicate as they are good at building up resistance to chemical treatments.
- Phytoseiulus: This is a predatory mite and arch enemy of the red spider mite. It is an effective hunter that will much through large numbers of red spider mites. During its life cycle, a single Phytoseiulus is capable of eating hundreds of mites.
Win the war on Slugs & Snails
Slugs and snails are on the top of my list for being the most destructive pests in my garden. I dread damp weather – the time in which slugs and snail are most active. During the day and dry weather, they hide in the soil. There can be as many as 200 slugs per square meter of soil. 1000’s of slugs and snails can be removed before you notice any difference. I would suggest trying a combination of methods:
- Nematode Phasmarhabditis hermaphrodita: Very effective at targeting slugs and snails, especially those hidden underground. The best time to apply nematodes is from March until October. You will need to water the nematodes into the soil during damp or wet weather. They should become very active within 3 days. Each application usually lasts for up to six weeks and is totally harmless to pet, other wildlife and children.
- Hand-picking: This is not the nicest method, but I have found hand-picking to be very effective. During damper nights (or every night if you have a lot of slugs/snails), go out into the garden with a torch. Squash or gather any slugs or snails you find. Although snails are easier to handle, slug slime can be very difficult to wash off hands. I would suggest you wear gloves. A friend of mine uses a very sharp knife to cut up the slugs when he finds them. This can be effective, but also very messy and not for the faint-hearted! If you do opt for this method, perhaps you could leave the carcases for the birds.
- Beer pots: Slugs and snails love beer to death! Place jam jars, plastic tubs or baked-bean tins into the soil and fill with the cheapest beer your can buy. Ensure that there is a gap between the rim of the jar/can and the soil of about 3 cm. This will prevent ground beetles and other beneficial insects from falling in and drowning. Ground beetles are a dreaded foe of slugs and snails. Empty each pot ever couple of days and refill with fresh beer.
- Organic slug and snail pellets: This is a very effective method. Organic slug and snail pellets contain Ferric Phosphate, which is harmful only to slugs and snails (please check the packaging for ingredients before buying!). Ferric Phosphate also feeds your plants, unlike the conventional pellets that contain the very toxic metaldehyde. Metaldehyde-based pellets are very harmless if eaten by humans, hedgehogs and frogs. There is an issue with using pellets. You may inadvertently reduce the amount of food for animals that actually feed on slugs and snails. It is all about balance! After consuming a pellet, slugs and snails will do the right thing; bury themselves and die. No sign of a fight and mess to clear up. Read more about organic slug pellets.
- Hedgehogs: I’m afraid that this one is a myth. Hedgehogs feed mostly on beetles and caterpillars. Slugs and snails only make up about 5% of a hedgehog’s diet. Also, it should be noted that slugs and snails are the primary carriers of lungworm. Lungworm (and the motorist) is the biggest killer of hedgehogs. Over half of all the hedgehogs brought into Wildlife Hospitals or Rescue Centres die because of a lungworm infection. Let’s not depend on these lovely mammals to do our dirty work.
- Copper tape: It’s a fact – slugs and snails hate crossing copper. They receive a small static shock on contact. Placing self-adhesive copper tape around your plant pots and planters will deter the majority of attacks. You need to ensure that there are no leafy bridges over the copper tape for the slugs and snails to cross. I have also had success putting copper tape around the legs of greenhouse staging as well as on the bottoms of bean canes. To protect my young runner beans, I place 10 cm segments of plastic pipe with a wrap of copper tape. These act as sleeves and are cost effective. Read more about copper tape.
Whichever method we adopt to control pests and weeds in our garden, we always need to consider the welfare of other species. Are we depriving them of valuable food or harming them in any other way? If we are, how can reassure them to return to our gardens?
I would like to encourage any of our readers to make other weed and pest control suggestions or success stories in the comments box below.
Natural pest control / herbicide resources
For more information and advice on organic natural pest control, please visit the following online resources: