Smart fixes to rid your garden of insects and disease

There's no reason for your vegetables, seedlings, flowers, plants or trees to be fighting against pests or diseases alone. The good news is, we're here to help: there's a whole slew of tricks to keep you winning this battle.

Spray cabbage and other vegetables targeted by caterpillars with onion juice, and watch the pests take a detour. To make a spray, peel two medium-size onions, grate them into a large bowl, and add 3.5 litres (one gallon) of water. Let the mixture sit overnight, then strain it into a spray bottle. To make the plants smelly enough to repel the pests, you may need to spray the leaves twice.

While hornworms are the largest of the vegetable garden caterpillars, they're also among the hardest to spot; their pale green colour camouflages them as they chomp on the leaves of tomato, potato and pepper plants.

To find hornworms, turn your garden hose nozzle to the fine spray setting and direct the spray to a plant. Any hidden hornworms will thrash about and reveal their whereabouts, at which point you can pick them off and drop them into a bucket of water. The hotter the day, the more of a shock the cold spray will be to a hornworm's system.

To keep cutworms and other crawlers from reaching newly planted seedlings, use soup cans as barriers. Cut the top and bottom out of a can, wash it well, and place the can over a seedling. Twist it until the bottom is five centimetres (two inches) underground, and tender seedlings will gain protection from all directions.

Keep powdery mildew, black spot and other fungus diseases from infecting your fruit trees, vegetables, gardenias, roses and such with a baking soda solution. In a large spray bottle, combine five grams (one teaspoon) of baking soda, five millilitres (one teaspoon) of dishwashing liquid and one litre (one quart) of warm water. Shake well and spray plant leaves and stems on both sides to discourage fungus diseases from taking hold.

It's long been known that roses grown next to tomatoes are less likely to fall victim to black spot. Make a fungicide by snipping tomato leaves from a plant and whirring them in a blender with a little water; use enough leaves to make 500 millilitres (two cups) of slurry. Combine with 1.5 litres (1.5 quarts) of water and 30 grams (two tablespoons) of cornstarch and mix well. Store the solution in the fridge, marking it with a warning label. Spray your rosebushes once a week with the fungicide.

You don't have to surround yourself with toxic chemicals to keep damaging insects and disease out of your garden. These homemade solutions will do the job and have your garden insect-free and flourishing in no time.