Protecting brassicas from cabbage worms

If you are growing cabbage, Brussels sprouts, broccoli, cauliflower, kale, radish, turnip, or rutabaga, you may need to take steps to protect your plants from cabbage worms.  These green caterpillars love to chow down on brassicas and similar plants; after they pupate, they emerge as small, cream-coloured moths (that have a couple of dark spots on their wings).

There are many natural ways to control them, such as attracting their predators into your garden.  One simple solution is to construct a cover made of tulle (a fabric commonly used to make prom dresses and the like).  This fabric mesh allows in rain and sunlight but prevents moths from entering and laying their eggs.

You don’t need to make anything fancy.  You can make a wire hoop frame, or simply set up some stakes that you can drape the fabric over so it does not sit on the plants (as I have done above, on my hail-damaged plants).  Place something heavy on the edges of the fabric, where they rests on the ground.  Or, you can construct something permanent.  There are plenty of ideas on the internet.

For more information on cabbage worms, and other methods of controlling them, see https://www.planetnatural.com/pest-problem-solver/garden-pests/cabbageworm-control/.

Rabbits in the garden

On Christmas morning, a pair of rabbits made their first appearance in the backyard.  They were seen feasting on spilled sunflower seeds alongside the birds.  Although rabbit manure is prized amongst gardeners, rabbits in the garden is another story.

How do you know if rabbits have eaten your plants?

If it looks like someone has come into your garden and snipped off the stems using clean, angled cuts, a rabbit was probably the culprit.

What do they eat?

Rabbits like beans, peas, parsley, rosemary, blueberry and other fruit bushes, young pepper plants, beet greens, and Swiss chard–they’re not all about carrots and lettuce!  They’ll also eat flowering plants, and tree bark.  They love roses.

They don’t like mature pepper plants, cucumbers, tomatoes, corn, squash, basil, chives, oregano, onions, and sage.

Deterring rabbits

If you have a dog that has free run of your backyard, you may not have a problem with rabbits.  The presence of dogs and cats, as well as their hair and urine, often deter rabbits.  Otherwise, here are a few tips.  You may need to use a few of them.

  • Apply to the perimeter of your garden one of the following: ammonium soap, hot pepper flakes, moth balls, blood meal, or a commercial spray that contains or mimics coyote or fox urine.  These types of deterrents should not be applied directly to the edible parts of plants.  They need to be reapplied after watering or rain.
  • Minimize hiding spots in your yard.  Rabbits need places to hide; if they don’t have them, they won’t feel safe in your space.
  • Plant marigolds or onions around the border of your garden.  The scent may drive them away.
  • Plant a small decoy garden a distance away from your own garden.  Sow their favourite plants for them so that they’ll leave your main garden alone.
  • Install a chicken wire fence around your garden.  It should be a minimum of two feet tall, and up to six inches underground.  Dig a trench and bend the wire into an L-shape so that rabbits cannot dig down and under the fence (here is a visual).
  • Install cages around individual plants to protect them.

Trapping and removing rabbits and other animals rarely works.  When a rabbit is removed from a space in which it was living happily, a vacancy is created into which a second rabbit can move.

 

Insects: our tiny garden friends

You’d think, from the language some pesticide manufacturers use, that most insects spend their days pillaging gardens.  The truth, though, is that up to 90% of insects are actually beneficial to the garden, or benign.  In addition to pollinating plants, breaking down organic matter, and aerating soil, they eat insects that do like to munch on our prized plants.

Broad-spectrum pesticides kill indiscriminately

Pesticides introduce harmful chemicals to our gardens, and kill both beneficial and harmful insects.  When you remove the natural predators from your garden, there’s nothing left to kill the second (and third, etc.) wave of harmful pests that will, inevitably, move in as they pass through your neighbourhood.  So now you have another type of insect to deal with.  You may find your garden is in worse shape than before because the natural predators weren’t there to protect it.

Attracting beneficial insects

A perfectly mowed lawn is not an inviting habitat for beneficial insects.  Gardens that contain a mixture of flowers, shrubs, herbs, and vegetables offer an inviting habitat for beneficial insects, as well as birds, bats, frogs, and toads.

Good bugs

Here’s a selection of bugs that help your garden:

  • Assassin bugs are well-named.  They eat many different types of bugs and their larvae.
  • Centipedes eat pests that live in your soil.
  • Ground beetles eat cutworms, caterpillars, slugs, and snails.
  • Hoverfly larvae eat aphids, cabbage worms and other small caterpillars, mites, and other pests. Adult hoverflies consume flower nectar, and help to pollinate plants.
  • Lacewings eat aphids, whiteflies, larvae, thrips, and mites.
  • Ladybugs, ladybirds, and ladybeetles eat aphids, mealybugs, and scale.  Their larvae eat mites.
  • Spiders, like the yellow garden spider shown above, catch pests in their webs.
  • Parasitic wasps lay their eggs inside pests, thus destroying the pest when the egg is hatched.
  • Pirate bugs eat a variety of insects, such as aphids, spider mites, and thrips.
  • Praying mantis eat a wide variety of insects, such as fruit flies, aphids, cockroaches, crickets, beetles, grasshoppers,  and caterpillars.

Bees and earthworms, it should go without saying, are also insect heroes of the garden!

The bad

Here’s a selection of pests that may damage your garden:

  • Aphids spread viral diseases to legumes, and damage leaves.  They have many natural predators, as indicated above, and can be removed with a spray bottle filled with water or a natural soap solution.
  • Many types of beetles and weevils can damage plants.  The best solution, in many cases, is to remove them by hand, shake them off the plants, or apply floating row covers to your plants.
  • Adult Japanese beetles eat flowers and leaves, and their larvae attack roots.  The best defence against them is to apply row covers to your plants.  You can also try applying a spray made of cedar oil.
  • Borers, as the name implies, bore holes in stems, which causes wilting and then death.  They attack plants such as melons, cucumbers, and squashes.  You can carefully cut them from the stem with a knife and then place the wounded part of the stem under the soil to encourage it to heal.
  • Caterpillars may eat plant foliage and fruit, and sometimes their roots.  Pick them off and destroy them.
  • Earwigs like to burrow in peppers and corn cobs and eat the tips of buds before they flower.  There are many ways to trap them, as they like small spaces.  They are nocturnal so you can empty the traps during the day.
  • Millipedes damage potatoes and may eat seedlings.  They like soil that is rich in organic matter, so be sure to regularly cultivate your soil.
  • Scale suck on plants and leave tiny bumps.  Remove these damaged parts and destroy them.  A soap and oil spray is effective against them when they are in their crawling stage.
  • Slugs and snails eat leaves and small seedlings.  They’re best controlled by birds and frogs, but you can also set traps for them.
  • Thrips suck sap from the upper leaf surface, and they may damage flower buds and prevent them from opening.

The variable

  • Ants aerate the soil and clean up debris and weed seeds, but they also consume the sticky substance created by aphids, and thus transport pests between plants.  If the aphids are controlled by the beneficial insects mentioned above, ants should not be a problem.
  • Nematodes are microscopic insects.  Some varieties feed on insects, and others, such as root knot nematodes and potato cyst nematodes, damage plants.  Crop rotation can prevent these from taking hold in your garden.

It’s not as dire as you think

Sure, there are a lot of insects that can harm your garden, but if you rotate your crops, attract beneficial insects and animals, and practice companion gardening, you’re likely to avoid most of them.