Members on the International Bulb Society Internet Email Bulb Robin Forum have discussed many methods of controlling pests and about using chemicals and herbicides to protect our precious plants from insect attack. But the question of using dangerous chemicals is always an issue in our gardens.
Our personal choice could be to not use chemicals at all. If a more natural method of control is possible, should we consider this? If we help nature will it reward us with beautiful flowers and healthier plants
Some reasons to try organic and alternative methods could be: members of the family may be allergic to certain chemicals; chemicals are generally not good for our health, or, for our pets; there are good insects in the garden that are beneficial and it would be wise to protect them. We should consider natural methods as a healthy alternative
One of the guests I use on my regular Saturday morning “Blooming good Gardening” program on 3BBR FM which was broadcast` in Gippsland Victoria, is an American botanist who has lived here for many years. Steve Lavalley owns a nursery called “The Botanic Ark” and grows many tree and plant species which he has collected over time. Steve is big on philosophy and one day I suggested that he do a segment for me on “good and bad insects” with the emphasis being that we shouldn’t use chemicals but rely on a more natural method of control to keep the status quo.
I suggested a ten minutes slot to him for this segment. He looked at me, frowning and said,
“Oh Bill, I would need a longer time to do that. If you really want me to do that in such a short time I could just tell everyone about one of God’s commandments.”
“Which one is that?” I asked
“Thou shalt not kill” was his reply.
I have researched some Australian growers and authors for their thoughts on pest control and here is a brief compilation of some of them for your consideration.
Australian bulb grower Bruce Knight, in his 1987 publication “Lachenalia for Australia” said, “ If use of insecticide or miticide is necessary, bear in mind that some sprays may cause more damage than the pests they are designed to control - not only by the burning of leaves or the marking or distortion of flowers, but also by their effect on garden ecology, the environment and possibly the gardener. ”
The publication “Flower Power in the Australian Bush and Garden” quotes: “Also, gardeners often kill the useful insects in the garden when they spray insecticides, making it easier for aphids and scale to breed quickly.”
Further quotes from “ Natural Gardening and Farming in Australia” state that: “When it is remembered that most agricultural chemical pesticides - particularly the chlorinated hydrocarbons - can persist in the soil for hundreds of years and concentrate in the food chains, then really, there are no safe levels of such chemicals. Every means possible must be used to develop alternative, natural methods of coping with insect and disease problems.” - “ The first thing to recognise when discussing plant protection from insect attack methods, is that plants themselves are not defenceless, but have their own means of defence against being eaten by insects.”, and, “Natural pesticides are present in many plants and can contribute up to 10 per cent of a plants dry weight.”
Jeffrey Hodges even suggests that these “so-called harmless methods” such as the ones suggested here, can do damage as well. He states: “It is a problem, however, with the snail or grasshopper or whatever attacks a young seedling, as it invariably destroys the whole thing! So what I try to do is to physically protect young plants from such attacks. This can be rather simply achieved by covering the most susceptible plants with flowerpots - or plastic cordial bottles cut in half - overnight for three or four weeks, until they are large enough to handle being nibbled a little. Alternatively, spreading around fresh grass clippings, wood ash or sawdust can discourage snails and slugs for a week or two. And, of course, there is hand collecting.”
Then, there is the issue of what we kill when we use pesticides. The “New Gardener Plant Doctor” states that: “ Knowing which insects and other creatures are on your side makes sense; these creatures will help you keep pest levels down without any effort on your part. Some creatures are essential to the plant’s productivity or ability to produce - pollinating insects such as honey bees, for example. Others are important in controlling pests; some larger creatures, such as bandicoots, birds, frogs, echidnas and lizards ( in Australia) eat pests that live close to or on the ground. Insect-eating birds also help to control garden pests at shrub and tree height. The numerous beneficial insects include ladybirds and their larvae, hoverfly larvae, lacewings and their larvae and ground beetles. Even commonly found wasps and ants are of use as they prey on many insect pests. Spiders and centipedes too will help to keep pest levels down as they catch and consume insects that could damage plants.”
“In most instances it is both environmentally and socially desirable to take a balanced view of pests and diseases rather than develop what might be termed a ‘spray happy’ mentality. The presence of a pest , and even the presence of some diseases, does not mean it is essential to apply an insecticide or fungicide. In some cases low levels of pest and disease organisms will be insufficient to cause serious damage to bulbs and can be tolerated.” This quote is from James Hitchmough’s “Garden Bulbs for Australia and New Zealand.
It is obvious that the use of chemicals will not cure all problems and all of these quoted statements are worth serious consideration, whatever country we live in.
Chemical sprays can kill an infestation, but constant spraying can lead to the pests building up a resistance to the chemical. Pest control in the garden can be handled by using basic integrated management practises.
Monitor plants on a regular basis and select an appropriate control.
Not all insects are pests and if chemical sprays are excessively used, beneficial insects will also be destroyed.
Identify these good insects in your garden and encourage their presence. Use natural controls rather than chemical sprays to protect these insects.
Some beneficial insects are:
Insects play an important role in our gardens and we ignore them on an everyday basis until they threaten our plants in some way. Ants, earwigs, thrips, mealybug, slugs, snails, scale insects, caterpillars and aphids are just a few that we encounter. In my garden I had a plaque of Harlequin bugs. It was suggested that instead of using a chemical spray that I drop them into a bucket of hot water. It was quite a task. I collected as many as I could. Eventually, they disappeared. That was about five years ago and they have never returned. I assume they didn’t like the hot water! It is often our experience that chemical cures are not always necessary.
Here is a collection of natural remedies using herbs and natural products. I have not used them all so I cannot personally guarantee their success. If you try them, let us know, or, share with us your own methods that you use, so that others may benefit also:
Use fresh or dried chillies and blend one cup of dried or 2 cups of fresh chillies with two cups of water. Spray fresh. This will kill caterpillars.
Chilli and Wormwood Spray Blend one cup of chillies and one cup of wormwood with one cup of water. Then, add five cups of water and bring to the boil. Allow this to stand for one hour. Strain and bottle.
This can be sprayed on plants and garden beds to repel possums, rabbits, snails and slugs. It also kills aphids, bean fly and white fly.
Note: Do not allow to come into contact with eyes or skin.
Comfrey Foliar Food
Before Comfrey flowers, cut the leaves and pack them into an old bucket or something similar with holes in the bottom. Place a plate or a tin lid on top and weigh it down with half a brick.
Put a plastic plant pot in an old basin and stand the bucket on the pot. After three weeks, there should be a quantity of brown fluid in the basin. Strain this and then bottle it.
Spray plants in the proportion of 15 ml (1 tbsp) comfrey liquid to 1 litre (1 pints) water and a few drops of liquid detergent. Put the remaining contents of the bucket on the compost heap.
Home made sprays may be stored safely for up to one month, providing they are in sterile, glass, screwtop containers.
Glass bottles or jars may be sterilised by placing them in cold water and bringing them to the boil, then simmer for 30 minutes. Allow the bottle or jar to cool in the water before using.
Correct labelling is essential. Include the date of making and the ingredients on the container and keep them in a safe place out of the reach of children and animals.
Boil equal parts of coriander and water for ten minutes. Strain and bottle. This is suitable for spider mites and aphids.
Elder Leaf Spray
Simmer 500 grams of Elder leaves in 3.5 litres of water for 30 minutes. Replace water lost as steam. Strain and bottle. This is a general pesticide suitable for aphids, caterpillars, thrips and black spot.
Feverview Spray (tea)
Pour boiling water over fresh or dried feverfew flowers and steep until fragrant. This can be used on a wide range of insect pests. it is said to be good for migraines - drink one cup every morning as prevention.
Garlic Spray (1)
Soak four garlic cloves for several days in one litre of cold water and then blend. This will kill ants, caterpillars and cabbage worms. A stronger brew can be made by using hot water and adding several red peppers, ground up, and adding two tablespoons of pure soap to help the spray stick. Use spray when solution has cooled .
Garlic Spray (2)
Chop 85 g garlic. Don’t bother to peel it. Soak it in 2 tablespoons of mineral oil for 24 hours. Add 600 ml water to which 7 g of soap has been dissolved (or as soapy a solution you can make). Strain and store in glass not metal, away from the light. Dilute with ten times the amount of water to begin with; then make it stronger if it isn’t effective. The smell isn’t as bad as you would expect and it doesn’t linger when sprayed.
Garlic spray can be used as a general insecticide in a wide range of situations, but its effect is variable, very effective sometimes not at all at others. Possibly harsh, arid conditions make it less effective. Remember, it is not a contact poison and must be eaten to be effective.
General Insect Spray
Crush three unpeeled heads of garlic and 90 ml (3 fl oz) liquid paraffin. Place in a bowl, cover and leave to stand for 24 hours. Melt 15 ml (1 tbsp) grated , oil-based soap in 500 ml (17 fl oz) hot water. Blend the garlic mixture with the soap mixture. When cooled, strain into a glass jar or bottle and seal. Keep it in the refrigerator. To use, dilute about 20 ml (4 tsp) of this solution in 2 litres (4 pints) of cold water. Spray fortnightly.
Cover Marigold flowers (not the English calendula flowers) with boiling, soapy water and leave overnight. Strain and this can be used for Aphids.
Dissolve 500 grams of dried milk in 4 litres of water and spray directly onto the leaves showing signs of virus diseases.
Soak cigarette or cigar ends in water for a week at the rate of 30 ends to 4 litres of water. Remove the filter ends first. This spray will kill scale insects and mealy bug.
Chop up one large unpeeled onion. Place in a blender with one litre of water and blend on a slow speed, to a milky consistency. This is useful for use on aphids and red spider mites.
Any kind of pepper sprinkled on wet leaves will protect them from caterpillars.
Pure Soap Spray
Dissolve 225 grams of pure laundry soap in 9 litres of water. This will kill most pests on your plants. Allow it to dry on plants and then hose it down the next day with clean water.
Red Pepper, Garlic and Onion Spray
Chop an unpeeled onion and a head of garlic. Simmer the onion and garlic with 15 ml (1 tbsp) cayenne pepper in about 1.5 litres (2 pints) water for 20 minutes. Cool the mixture, pour into a jar, seal, stand for six weeks and strain into bottles. To use, mix 15 ml (1 tbsp) of this mixture with 750 ml (1 pints) water. Add a little soap solution. Use as a general pest spray as well as for caterpillars. Note: Do not allow this to come into contact with eyes or skin.
Simmer one kilo of rhubarb leaves in a covered pot for 30 minutes. Do not use an aluminium pot. When cool, mix with a little pure soap, enough to keep a permanent lather. The use of rainwater will increase the effectiveness as some salts present in mains water can reduce the strength of the oxalic acid content.
Sprinkled around plants, it is a deterrent to many pests, including slugs and snails. It contains elements that irritate and insects are reluctant to cross the barrier. Ensure you do not leave gaps.
Simmer 225 (8 oz) wormwood leaves in 2 litres ( 3 pints) water for half an hour. Stir, strain and leave to cool. Dissolve 5 ml (1 tsp) soap flakes in 500 ml ( 17 fl oz) hot water. Combine this with the wormwood water and spray plants frequently at the height of the caterpillar season. A strong wormwood tea, cooled and poured on the tracks of slugs and snails will deter them.
White Cedar Spray
Place white cedar leaves in a bucket. Cover with boiling water. Put the lid on the bucket. Steep until cold. If the liquid isn’t pale brown, you need more leaves. Don’t inhale the steam and don’t store it. Keep away from children. This will kill most pests.