This is the hand-out from the Resource Guide at the Green Gardening 2004 seminar held at the Royal Botanical Gardens on Saturday, 28 February 2004.
Natural Advice for the Home Garden
Natural Insect Pest Control
It is often much easier (and less expensive) to use natural insect pest control methods that frequently are made from readily available household ingredients, but first, why not try some strategies to prevent insect pests from even getting started?
Companion Planting: Some plants are effective deterrents to certain pests. For example, plant marigolds among squash and cucumbers to repel cucumber beetles. Other plants attract beneficial insects that control pests. Some of these are fennel, dill, parsley and thyme, and many carrot and mint family plants.
Crop Rotation: Plants from the same families (e.g. tomatoes and peppers) should not be planted in the same spot every year to avoid the build-up of pest populations, and to encourage a more balanced utilization of soil nutrients in the long term.
Healthy Soil: Over-fertilizing with chemical fertilizers actually encourage the reproduction of pests like aphids and spider mites. You can never over fertilize with compost!
Physical Barriers: Floating row covers prevent flying insects from ever reaching the vegetable crops, while letting light and water pass through.
Before resorting to any applied treatments for pests or disease, attempt to resolve the problem by removing the diseased parts of plants, carefully spraying a stream of water to physically remove insects (dont forget the undersides of the leaves!) And hand-picking larger insects such as Cabbage Loppers and Colorado Potato Beetles.
Some Home Remedies for Controlling Pests and Disease
|Simple Soap Solution
||2 tbs. Soap Flakes / Liquid (pure unscented soap not dish detergent).
1 L of water
Mix well and spray on plants or lawn.
|Soft-bodied insects such as aphids, white flies, mites, caterpillars, cinch bug.
||85g of minced garlic
2 tsp. Mineral oil
600 ml water
1 tsp. Soap (see above)
Soak garlic in mineral oil for 24 hours. Strain out garlic, add water and soap, mix well. Mix up to 2 tablespoons of solution in 600 ml of water and spray on affected plants
|Aphids, Cabbage Worms, Squash/Cucumber Beetle.
Warning: can kill beneficial insects and cause plant damage. Use with caution.
||1 tsp. Baking soda
1 L water
up to 1 tsp. Soap flakes
Dissolve soda and soap in water. Spray on plants.
|Powdery mildew and black spot.
|Soap and Oil
||1 tbs. Soap (see above)
1 cup oil (peanut, safflower, corn, etc.)
1 cup water
Combine soap and oil. Mix only 1-2 tbs. Of soap and oil to water. Spray.
|Pests on cucumber, eggplant, lettuce, peppers.
||1 bar Neem Soap (from health food store)
1 L water
Shave 1 tbs. from soap bar. Add to water and sit for 1 hour.
|A range of plant pests.
Natural Plant Pest (Weed) Control
A weed is simply a plant growing somewhere that we dont want it. There is no such thing as
a plant classification of weed and in many cases one gardeners weed is anothers salad! Many
so-called weeds such as milkweed are very attractive to beneficial insects that eat insect pests. Other, such as
dandelion and common purslane are delicious edibles. Still, this doesnt mean that we want them everywhere,
so here are some simple, non-chemical strategies for dealing with unwanted invaders.
Prevent Seedling: Dont let weed plants go to seed. The gardeners saying, One years seeding
makes seven years weeding is no exaggeration! Remove them before they mature.
Remove Seedlings: Remove small weeds before they become established. Learn to recognize young weed seedlings
and eliminate them before they become established.
Mulch: a 3-6 cm thick layer of organic mulch as compost, shredded leaves or fine wood/bark chips keeps sunlight
from reaching weed seeds, preventing them from germinating and growing on. Mulch immediately after weeding or
digging the soil. Keep mulch away from established plant stems to prevent rot, and if you mulch with compost, enjoy
the added benefit of fertilizing your garden and at the same time. For heavily weed-infested areas, and for noxious
plants such as Poison Ivy, cover the area with a layer of newspapers of minimum six pages thick, then cover the
newspapers with a mulch layer. You may have to wait for a year, but you will be rewarded with a weed-free patch.
Corn Gluten Meal: Corn gluten meal has been demonstrated to be an effective suppressant of broadleaf
germination. It also serves as a fertilizer as it breaks down.
Plant Densely: Grow the plants that you want close together. They will consume space, nutrients and sunlight,
preventing weeds from establishing.
Pull: ...dont yank perennial weeds such as Dandelion. Although many weeds are easily removed, if the deep
roots of perennials are left behind, then another plant will eventually sprout. Special weeding tools are widely
available that can make the job easier.
Moist Soil: Do your weeding after a soaking rain. You will be surprised how easy it is to remove those otherwise
impossible-to-pull Dandelions and Broadleaf Plantains!
Other Extreme Methods: For pesky places like cracks in sidewalks and interlocking brick, use an
application of boiling water to kill weeds, or a weed torch (available from many garden suppliers such
as Lee Valley Tools) to burn them away. These methods sometimes must be repeated, but will eventually prevail.
Finally, trying to achieve a weed-free garden is unrealistic. Learn to live with a few uninvited guests and relax!
Harry Jongerdens Tips for a Healthy, Pesticide-Free Lawn
- Aerate. One of the major causes of weeds in Canadian lawns is soil compaction. Rent a machine or hire
someone to aerate your lawn in the early spring or fall. The machine will create small grass and soil
plugs that should be left on the lawn. Rain and lawn mowing will break them up. You can also
aerate by hand with a digging fork, the kind with four wide tines. Simply stick your fork in the soil to a depth
of 3-4", wiggle the handle back and forth, then remove along methodically and repeat. This is especially
useful in tight corners or the worst of your compacted areas.
- Top-dress. If you wish to thicken your lawn in sparse areas (and crowd out potential weeds!), you should
top-dress after aerating. Top-dress by spreading a thin layer of compost or triple-mix topsoil
to a depth of 3/4". Your existing grass will poke through and survive as you add grass seed.
- Over-seed. After you have aerated and top-dressed, your lawn is ready for over-seeding. Most grass seed
comes as a mixture of different grasses. For the following growing conditions, choose a mixture with 50%
or more of the recommended seed type.
Full sun: Perennial Rye grass. This seed has far superior drought tolerance compared to Kentucky Blue.
Shade: Creeping Red Fescue and/or Chewings Fescue.
The grass seed mixtures you need will also contain some Kentucky Blue and other seed. This is not a
problem. A variety of grasses is good, provided the majority is appropriate to your conditions.
Gently fan-rake after over-seeding to ensure that seed id in contact with soil. You must keep an over-seeded
area moist during and immediately after germination.
- Water adequately and at appropriate times. The plan is to encourage deep root growth, which allows your
grass to withstand harsh conditions. In the early morning, before the sun gets too hot, or in the cool of the
evening, water deeply (approximately 1" of water). Place a broad pan on the grass to find out how long it
takes to sprinkle 1" from your hose. Watch for drought symptoms where grass turns darker green and leaf
blades fold inward. If water restrictions are in effect, a lawn comprised of Perennial Rye grass can survive
a drought and then revive in cooler, wetter weather.
- Mowing. Mowing your lawn too short will damage or kill the grass, especially in hot, dry conditions. During
summer months, especially, raise mower blades to at least 2". If your machine is not adjustable, consider
retiring it. A mulching mower, with adjustable wheels and sharp blades, is best. Leave grass clippings on the
lawn, as well as mulched fallen leaves. No need to rake leaves when youre mulching and creating
- Feeding. Lawns can be fertilized in spring and in fall. Never fertilize a lawn that is stressed by summer heat.
Avoid chemical fertilizers that get their nitrogen from urea formaldehyde and other synthetic
sources. More natural fertilizers are available to help create healthy soil. These fertilizers derive their nitrogen
from a variety of animal-based meals fish meal, poultry meal, blood meal and bone meal
as well as plant-based meals such as corn gluten meals or canola seed meal. Be cautious about animal based
products however, because these are not tested for levels of pesticides or heavy metals that were accumulated
during the lifetime of those animals, and may be a source of these substances to your garden. When you avoid
the use of herbicides, clover will become a valuable part of your lawn. It will feed the grass it grows amongst
because clover produces nitrogen.
Note: It has been found that fall fertilizing benefits grass greatly by strengthening the roots. Apply when
temperatures are 8-10 degrees by day and approaching freezing at night.
- Dethatching. If thatch is more than 0.5" thick, dethatching is advised to enhance drainage and remove a
potential breeding ground for pests and disease. Do this in the spring after the first spurt of new growth, or
in the fall. Any other time is too stressful for your lawn.
- Pests and Weeds. What constitutes a weed anyway? Pull unwanted weeds by hand, or hire
a young neighbourhood entrepreneur to do it for you. Corn gluten meal applied in the spring (before the
forsythia blooms) will prevent crab grass germination, but be sure to wait a month after application to
over-seed because corn gluten meal will interfere with the germination of good grass as well. Explore
chemical-free ways of dealing with grubs, although youre unlikely to have many of them when your lawn is so
healthy because of following the methods above. Microscopic nematodes, applied to lawns when spring
temperatures reach 15 degrees, will keep your problem grubs in check.
- Turf Alternatives. Consider low-maintenance alternatives which can be attractive to look at, as well as
providing food and shelter for wildlife.
- Be patient. As your lawn adjusts to a more natural state. It takes time to welcome back the clover, worms,
beneficial microorganisms and other members of the ecosystem during the transition to a pesticide-free lawn.
For more information about lawns the pesticide-free way, contact the experts at Green Venture
(www,greenventure.on.ca). They have a kit called Pesticide Free Naturally that is full of information.
Compost: As Organic as it Gets!
Using compost derived from your plant waste is the easiest way to ease your garden off of its chemical diet.
Although we call it composting, we are simply mimicking the processes of plant death and
decomposition that occur throughout nature that build soils and provide nourishment for plants and beneficial insects,
bacteria and fungi. This natural (slow and steady) approach has many benefits over chemical fertilizers and other
garden additives, not the least of which is that it is virtually free.
Chemical high-nitrogen fertilizers unnaturally speed plant growth, making them weak and subject to fungi
and disease. Even when applied according to directions, domestic chemical fertilizers are rarely all taken up by plants
they were intended for, and instead percolate through the soil to the water table contributing to the degradation
of ground water quality. Sphagnum (peat) moss is marketed as an organic soil amendment to improve
structure, but it contains virtually no available nutrients and its purchase contributes to the destruction of unique
wetlands habitats in Canada that have taken thousands of years to develop. For adding nutrients and improving soil
structure, compost beats commercial products hands-down, and making a high quality, balanced, organic compost
- Although commercial composters are widely available, they are not required. You may choose to build one
from a decay-resistant wood such as cedar, or simply make an old-fashioned compost pile if
you have space. If you choose to build one from wood, do not use pressure-treated wood (that contains
copper and arsenic) or apply chemical treatments or paint. This is particularly important if the compost is to
be used in your organic vegetable garden.
- Place the composter in a sunny place if possible. The suns warmth will speed decomposition.
- Add both higher nitrogen green material and drier brown material such as fallen leaves. Add these in
alternating layers or mixed together. Chopping or shredding materials into smaller pieces will make the
composting process go faster. Remember: you will not have organic compost if it does not
have organic ingredients. Avoid grass clippings that may have been chemically treated, for
example. Also avoid diseased or invasive plant material.
- Keep the compost moist but not wet. Use a cover if it becomes too wet from rainfall, loosen it and work in
dry material such as leaves. If it gets too dry, water it!
- Aerate the pile every two to three weeks by turning it with a pitchfork, shovel or aerating tool.
- The compost is ready to use when it is dark and crumbly, with most of the original identity of the materials
lost. You may choose to sieve the finished compost to remove large material such as twigs.
- The most natural (and easiest) way to apply compost is as a thick top-dressing to all your garden beds in the
spring. You can also use it as a effective lawn top dress and seed staring mix.
||Not enough air or too wet.
||Turn to aerate; add dry material.
|A Raccoons in my composter!
||Meat, fish, dairy products in composter.
||Never add these materials to your composter.
|Nothing is happening!
||Compost is too dry
Compost if frozen
Poor carbon:nitrogen ratio
|Moisten and mix thoroughly
Be patient and wait until spring
Generally adding more green material
(e.g. plant cuttings) will help
Soaked with rainfall
Lack of air
|Move composter/pile to a location with better drainage
Add dry leaves or use a lid
Aerate with a pitch fork, shovel or aerating tool
Gardening with Native PlantsIf you want a low-maintenance garden that is easy to maintain without pesticides, you need look no further
than the nearest natural areas. The Native plants that grow in nearby conservation areas and natural parks have
adapted to local soils and climate for a very long time and are ideal choices for your home garden. Not only do these
plants look right at home and require little care, but they also help to form urban habitat islands that attract wildlife
and act as stopovers for migrating birds and other animals. As our cities grow larger, the role that these urban habitat
islands also becomes more important in maintaining natural biodiversity in our area. The fact that these plants are
resistant to local pests and climatic conditions is a bonus that allows us to grow them without having to use
pesticides. Many North American natives are disdained by local gardeners as being too ordinary, but gardeners
around the world have sought out and coveted our native plants as choice specimens in their gardens. We are lucky
to have a diverse flora in the Golden Horseshoe area we should learn to appreciate what these plants have to offer
It should be noted that whenever you are purchasing native plants you should make sure that they were not
harvested from the wild, but grown by the supplier, preferably from local stock. Never collect plants from the wild
yourself. You might find a spot where the species appears abundant but the patch you find may be one of a very few
and every individual is important to maintaining the strength of that population. Many natives are very susceptible
to disturbance, especially our lovely spring ephemerals such as Hepatica and Trillium that appear only in the spring
and are dormant and invisible for the remainder of the year.
Native Planting for WildlifeIf you want to attract wildlife to your garden, the best way is to provide them with all of their needs in one
place: cover, water and food.
Water can be provided by having a pond, bird-bath or other water feature in your yard. To attract birds, the edge
should have a gradual enough slope to allow the sipping and shallow bathing that birds require. Many birds prefer
water with an open edge and an edge sheltered by vegetation. In winter, you should let the water freeze birds
normally eat enough snow to sustain them. If you are considering keeping a patch of water ice-free for animals to
drink out of, make sure that the open area is very small, or covered with a mesh barrier so that birds cannot bathe
in it, thereby making them susceptible to freezing.
Cover can be provided with constructed items such as roofs on feeders and nesting boxes, and by piles of logs and
old hollow trees left standing. Old dead trees are important for both birds and mammals as nesting sites, feeding
perches and as food sources since they often contain many insects. Cover can also be provided by plants. Trees and
shrubs are important cover plants for many animals, but smaller plants can be too, especially for birds and insects.
Food can be provided in the form of bird-seed and other purchased foods for wildlife such as nuts, but the best food
for native animals that eat mainly berries and seeds is that supplies by native plants. Selecting the best plants for your
area can be a daunting task.
A word about Naturalization:
Naturalization is the process by which a landscape increasingly appears like a natural landscape which makes it
more appealing to wildlife. This may be a natural process where an impacted site recovers, or a process controlled
by humans, such as in restoration projects. Ideally, this means that the plants are all native, but even if you have a
mix of native and non-native plants in your yard, you can plant them in a naturalistic way that resembles the layers
and patterns found in nature. This will attract wildlife while allowing you to enjoy all of your plants, native and non-native alike.