One of the most challenging activities in the garden is pest management. Initially, you may feel helpless as multiple pests can attack your garden. Over time, you’ll come to expect the pests, you’ll get to know which pests attack which plant families and when, and you’ll know how to deal with each pest. Until then, there are a few key steps in the pest management process:
Since you can never get rid of pests, the easiest way to manage them is to prevent them from getting to your vegetables in the first place. There are a few key strategies for doing this.
Timing is your easiest strategy – plant your vegetables when the pests aren’t expecting them. For example, plants in the cabbage family are susceptible to early pests such as aphids or flea beetles. Planting these in late summer (for a fall harvest) can be much simpler than trying to make them work in the spring when the pests are just emerging.
A defence for flying pests and some rodents is row cover. This is ideal when you can’t avoid the pests through timing. Row cover is a fine mesh fabric that you drape on top of your vegetables, either directly on top or strung over hoops to give your vegetables room to grow. Make sure to sufficiently weigh down the row cover on all sides to prevent wind gusts from blowing it away.
Crop rotation is another key pest prevention method. If you grow the same crop in the same place for multiple years, the pests for that crop are likely already in the soil beneath your plants, so your vegetable are at a disadvantage the moment your plant the seeds. Move plant types around in the garden from year-to-year to make it more difficult for the pests to find them.
Finally, companion planting is an easy method of pest prevention. Place a select group of plants beside your vegetables to deter pests from attacking them. Companion plants protect your vegetables in one of two ways:
- Their aromatic nature will confuse or even repel pests and thereby disguise your vegetables. This is often done by members of the mint family (peppermint, basil and sage deter flea beetles, hornworms and cabbage moths) and the carrot family (dill and coriander deter hornworms and aphids).
- They can be used as “trap crops”, which is to say that they are planted with the intention of becoming a better target for the pests. Nasturtiums and tobacco are great plants to place near squash, eggplants and potatoes as they make a more appealing target than your vegetables.
Despite your pest prevention efforts, some pests will still find your plants. The first step in dealing with them is to identify them. If you can see the pest, the easiest way to identify it is through a smartphone app such as Seek or iNaturalist.
It becomes more difficult if you can’t see the pest. In this case, you need to combine the type of damage with the plant family being damaged.
For the type of damage, there are three broad categories:
- Sap suckers, such as aphids and squash bugs, weaken the plant by removing nutrients from inside
- Defoliators, such as slugs, potato beetles and cabbage worms, eat chunks out of the leaves
- The larvae of leaf miners, such a beet leaf miner, tunnel inside the leaves of vegetables
If you can classify the type of damage, then search that combined with the plant family and you’ll usually be able to determine the culprit.
Even after the pests have found their target, you can still control them and minimize the damage. Wherever possible (or palatable), try to manually remove the pests by hand-picking them. Failing that, here are some food-safe and organic pest control options:
- Soap solution – Use 1 tsp of castile soap per 1 liter of water in a spray bottle. Use for aphids, moth larvae or squash bugs.
- Diatomaceous earth (“DE”) – Buy food-grade DE by the bag and then funnel it into a squeeze bottle for light dusting onto plants. Use for slugs and snails, potato bugs, aphids, tomato hornworms, cabbage worms, and flea beetles.
- Compost tea – Make or buy compost tea and funnel it in a spray bottle. Use a 1:1 tea to water ratio if applying directly to plant leaves, or use 100% compost tea if applying to the soil. Use for damping off, blight, and for general plant health.
- Baking soda solution – Combine 1 tsp of baking soda, 2-3 drops of castile soap and 1 liter of water in a spray bottle. Use for powdery mildew and blight.
- Aromatic spray – Combine 1 liter of water, 2 cloves of crushed garlic, 1 tsp of lemon juice and 2 drops of castile soap. Let this mixture brew overnight and then filter out the garlic cloves and keep in a spray bottle. Use for aphids, squash bugs and some rodents.