Aphids just love artichokes just as much as I do.
When Bugs do Bad Things
There are numerous methods to control insects. It is always best to start of with the least toxic and if that doesn't work, change it up to the next option until the problem is resolved, or you decide to give in and toss the plant. It happens.
When it comes to the vegetable garden, I would rather chuck out the infested plant rather than spraying with chemicals as they are generally easy to replace. In fact, I steer away from using chemicals to kill insects on plants, even ones I am not going to eat. I do rotate crops, practice companion planting and improve soil with compost etc. I also mulch were applicable and keep up with the watering during the heat of the summer. Harvesting promptly and not allowing fruit and veggies not to rot on the plant is another way to reduce pests. That is one thing I tend to fail at, as harvesting is often a daily chore and it is difficult to keep up. I also often use cloches as a barrier to prevent flying insects such as adult leaf minors, cabbage butterflies and carrot rust flies from infesting susceptible crops. I do my best to select insect resistant veggies. When I buy seeds and plants I look for resistant varieties. Just check their label as it will be noted.
When it comes to the vegetable garden, I would rather chuck out the infested plant rather than spraying with chemicals as they are generally easy to replace. In fact, I steer away from using chemicals to kill insects on plants, even ones I am not going to eat. I do rotate crops, practice companion planting and improve soil with compost etc. I also mulch were applicable and keep up with the watering during the heat of the summer. Harvesting promptly and not allowing fruit and veggies not to rot on the plant is another way to reduce pests. That is one thing I tend to fail at, as harvesting is often a daily chore and it is difficult to keep up. I also often use cloches as a barrier to prevent flying insects such as adult leaf minors, cabbage butterflies and carrot rust flies from infesting susceptible crops. I do my best to select insect resistant veggies. When I buy seeds and plants I look for resistant varieties. Just check their label as it will be noted.
Methods of Insect Control
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Panti-hose protects an artichoke flower from certain aphid infestation.
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Physical Insect Control
19th centuryHandpicking is the easiest, quickest and most effective, nontoxic method of controlling insects. If that is not your cup of tea, use a garden hose to help you wash them off. I hold the hose with one hand, then squish with the other. It works great with aphids and makes the process less unpleasant.
Pruning off infected plant parts and discarding them, is another easy way to control pests and diseases without spraying. Don't compost them though, and disinfect your pruning tools afterwards. I use a tablespoon of Pine-sol or Lysol to a gallon of water in a spray bottle.
Barriers block insects from getting to susceptible plants. To stop aphids from feasting on my artichokes, I fit panti-hose over their heads before the aphids find them. No spraying needed. Speaking of barriers, have you heard of a cloche? Originally from 19th century France, large glass bells (cloche is French for 'bell') where placed over individual plants to protect them from cool temperatures and insects, like a miniature greenhouse. This term is often loosely used for crop protection barriers including 'row covers'. Similar to hoop houses but much smaller, row covers protect non-fruiting vegetable crops as ones that need pollination to produce a crop are protected from all insects including bees.
A row cover consists of hoops inserted into the ground covered with a breathable fabric called spun-bonded polyester. This lightweight fabric allows air, light and water through, but not bugs. It prevents aphids, cabbage moths, carrot rust fly, leaf minors and other flying pest from infesting plants as they grow. Plastic may also be used instead of the fabric, however, water and air cannot penetrate through. During the summer, heat and condensation builds up under a plastic covered cloche so in needs to be watched closely and opened to air it out. In other words, it is a bit more work than the fabric. Cloches are also used to extend the seasons as the spun-bonded polyester provides insulation against the cool air in spring as well as the autumn.
To make a cloche, use hula hoops cut in half or PVC tubing. Hammer rebar into the ground leaving a few inches out of the ground, then insert the ends of the PVC or hoops onto the rebar). Secure all the ends with fabric with pegs or pins designed for the job or make your own with heavy duty wire (coat hangers work well) bent into U shapes.
Pruning off infected plant parts and discarding them, is another easy way to control pests and diseases without spraying. Don't compost them though, and disinfect your pruning tools afterwards. I use a tablespoon of Pine-sol or Lysol to a gallon of water in a spray bottle.
Barriers block insects from getting to susceptible plants. To stop aphids from feasting on my artichokes, I fit panti-hose over their heads before the aphids find them. No spraying needed. Speaking of barriers, have you heard of a cloche? Originally from 19th century France, large glass bells (cloche is French for 'bell') where placed over individual plants to protect them from cool temperatures and insects, like a miniature greenhouse. This term is often loosely used for crop protection barriers including 'row covers'. Similar to hoop houses but much smaller, row covers protect non-fruiting vegetable crops as ones that need pollination to produce a crop are protected from all insects including bees.
A row cover consists of hoops inserted into the ground covered with a breathable fabric called spun-bonded polyester. This lightweight fabric allows air, light and water through, but not bugs. It prevents aphids, cabbage moths, carrot rust fly, leaf minors and other flying pest from infesting plants as they grow. Plastic may also be used instead of the fabric, however, water and air cannot penetrate through. During the summer, heat and condensation builds up under a plastic covered cloche so in needs to be watched closely and opened to air it out. In other words, it is a bit more work than the fabric. Cloches are also used to extend the seasons as the spun-bonded polyester provides insulation against the cool air in spring as well as the autumn.
To make a cloche, use hula hoops cut in half or PVC tubing. Hammer rebar into the ground leaving a few inches out of the ground, then insert the ends of the PVC or hoops onto the rebar). Secure all the ends with fabric with pegs or pins designed for the job or make your own with heavy duty wire (coat hangers work well) bent into U shapes.
A row cover protects crops from insects and is a season extender.
Inside the 'cloche' plants are protected from insects and are slightly warmer.
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Install the row cover as soon as you plant your seeds and plants.
Bend PVC over the bed and insert the ends into rebar that has been secured into the ground.
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This trap is designed to trap wasps.
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Traps: There are many kind of traps available depending on the insects you wish to lure to their demise, including wasps. Some traps are yellow and sticky to attract flying insects, while others are bated with hormones called pheromones. Different pheromones are used to attract specific pests such as moths, borers, scale insects and many other insects. There are many types of insect traps available. They are commonly sold at garden centres and home hardware stores.
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Wasps are great pollinators and beneficial insects, however, having a troublesome nest close by, a trap is often necessary.
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Tree Bands: To protect trees from caterpillars and other overwintering pests, use tree bands. Plastic covered with a sticky Vaseline types substance called Tanglefoot, is wrapped around tree trunks to stop insects in their tracts - literally. The Tanglefoot stops insects (gypsy moths, cankerworms, weevils and many types of caterpillers) that have overwintered in the soil from climbing up trees in spring. It works! Wrap tree trunks in November and remove in March. Tree banding kits are available at most garden centres including Lee Valley Tools.
Tree bands are an effective barrier to prevent insects from crawling up trees.
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That brown stuff is actually Tanglefoot, a sticky substance that traps insects.
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Biological Control
Bacillus thuringiensis is a bacterial control that only kills caterpillars.
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Biological controls involve using living organisms to combat specific insect pests. Bacillus thuringiensis (Bt), is a bacterium that only infects caterpillars: cabbage loopers, tomato hornworms, corn borers, earworms. Avoid spraying it near butterfly gardens for obvious reasons.
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A cabbage white butterfly caterpillar.
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Plant eating insects are food for many organisms such as frogs, toad, snakes, birds and spiders. Lady bugs, centipedes and other beneficial insects also devour plant predators. To encourage birds to visit your garden consider putting out a birdfeeder and a birdbath. Plant shrubs and trees for birds to nest and hide from predators. Encourage toads and frogs by placing clay pots on their side and burying them halfway, making a wee cave for them. Or purchase frog and toad houses at a garden centre. Place their homes near water such as a small pond or water filled ditch. Provide them with a shady location where there is lots of foliage like under a shrub.
Frogs and toads eat many insects and should be encouraged.
Beneficial Insects
Tansy and Queen Anne's lace attract beneficial insects such as lady bugs, lacewings and parasitic mini wasps.
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Why should we, as gardeners, do more work than we have to? Why should we kill insects when there is a host of insects that are designed to do that very same job? Ladybugs are the most common carnivore, but there are many other insect eating insects out there.
You can buy beneficial insects, but if you do, get them from a local source so you know that they will eat your local bugs rather than some slightly different one from somewhere else. Also, they will be better adapted to your climate. Do your research to find reputable local dealers that will assist you. It is a bit tricky getting store-bought beneficial insects to work. You must plan ahead, conditions must be right and once they emerge they must have food. If they don't find food in your yard, they will dine elsewhere. They are not yours to keep no matter how much you pampered them and paid for them. They have no loyalty, but they do have appetites. |
Instead of purchasing beneficial insects, entice local ones to your garden with nectar and pollen. While they dance and sip among the flowers, they pollinate as they go. Even flowers from carrots, broccoli and other vegetables, attract many beneficial insects. Just allow a few carrots to flower; you'll be surprised to see how many insects will dine there. Carrot flowers are a member of the Umbellifera family. Their umbel shaped flowers provide a place to stand while they feed on the sweet nectar and pollen. They can rest and eat at the same time. The syrphid fly loves this type of flower, however, its larva feed on aphids, mites, scale insects and thrips. Sunflowers, asters, daisies and many other common garden flowers also attract all kinds of beneficial bugs.
Many beneficial insects are attracted to the honeydew, a sweet secretion exuded by aphids, whiteflies, scales and other sucking insects. To encourage the beneficial insects, lady beetles and lacewings, spray infested plants with a sugar spray. Combine 1 tablespoon of sugar to 1 cup of water and they will come to feed on the sweet water and feed on their prey.
Here are some beneficial insects, the plants they feed on and their prey.
Many beneficial insects are attracted to the honeydew, a sweet secretion exuded by aphids, whiteflies, scales and other sucking insects. To encourage the beneficial insects, lady beetles and lacewings, spray infested plants with a sugar spray. Combine 1 tablespoon of sugar to 1 cup of water and they will come to feed on the sweet water and feed on their prey.
Here are some beneficial insects, the plants they feed on and their prey.
Beneficial Insects
There's all different kinds of ladybugs, not just the red and black ones.
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Although this looks rather menacing, it is the larvae of a ladybug.
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Ladybugs, Lady Beetles, Ladybirds:
- Adults and are small round beetles usually red with black spots and wings.
- Larvae are ¼ inch long and are shaped liked alligators with orange and black spots or stripes.
- Both larvae and adults feed on aphids, mealybugs and many insect eggs.
- They will migrate to other gardens in search of food.
- Prefer a diverse plant selection such as shrubs, trees and many kind of flowers; they are not too fussy.
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Lacewings & Aphid Lions:
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Asters and other members of the aster family attract the beneficial lacewings and aphid lions.
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Parasitic Wasps (Parasitoids):
- Small up to ¾ inch long adult wasps pollinate, feed on nectar and don't possess stingers.
- Adults lay eggs in many types of caterpillars including tomato hornworms and cabbage worms, as well as aphids and whiteflies.
- Their white eggs are attached to the outside of the host insect, which they devour from the inside out when they hatch.
- Grow: dill, Queen Anne’s lace, asters, daisies, echinacea, black-eyed susan, goldenrod and flowers of carrot, celery, parsley, fennel, caraway, cilantro, parsnip, angelica and anise
To attract parasitic wasps, allow parsley, dill and carrots to flower.
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Woolly bear caterpillars are prey to parasitic wasps.
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To attract tachinid flies allow members of the carrot family to flower, like this cilantro.
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Tachinid Flies:
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Syrphid Fly, Hover Flies, Flower Flies
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Alyssum attracts numerous beneficial insects.
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The ground cover, crimson clover, attracts beneficial ground beetles.
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Ground Beetles
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Parasitic Nematodes:
- Microscopic eel-type worms poison and kill their host with a deadly bacterium.
- There are many kinds and selection depends on the insect pest you want to control: cutworms, grubs, cucumber beetles, flea beetles, sod webworm, to name a few.
- Purchase from a knowledgeable reputable dealer.
- Tricky to use as effectiveness is dependent on weather conditions and application and repeat applications are required.
Chemical COntrols
Apply dormant oil/lime sulfur combo before trees and shrubs leaf out in spring.
Sometimes, treating a plant to rid it from invaders is necessary. Use the least toxic products to reduce contamination of plants, the soil and the environment. This is especially relevant for edibles.
- The combination of dormant oil/lime sulfur is quite effective to kill overwintering insects and diseases. Use in January or February on deciduous trees and shrubs, including fruit trees and roses, before they start to bud.
- Spray entire plant and ground thoroughly including stems, trunk and under the leaves.
- If you need to spray, soap and water is the usual first line of defense. Mix 1 tablespoon of soap per quart of water with 1 teaspoon of vegetable oil.
- Effective commercial organic insecticides include Ultra Fine Oil, Organocide, pyrethrin and neem oil.
- Read and follow the instructions of any product to the letter before applying pesticides. Wind and temperature play a major part in a product's effectiveness.
- Reapplication is often necessary, usually 7 to 10 days, to kill subsequent populations that you missed the first time as well as their offspring.
- Avoid spraying any plant with anything in full sun as it will cause severe tissue damage and leaf loss. It’s also best to spray in the early morning or late in the day.