May 3, 2013

Dealing with insects in the garden

There are literally hundreds or thousands of different insects that find their way in and through our gardens every year.  Some are there all the time, some just come and go.  Most are harmless to you and your plants and lots are even helpful.  Encouraging them is worth the effort.  Some insects (the pests) are annoying.  Some are destructive and have a significant impact.  Managing them is a challenge.  Regardless, we first have to accept that insects are there (whether we like it or not) and from there we can move to minimizing the impact of the pests.

What follows is a brief and simplified list of some the things that you might consider doing (alone or in combination) to minimize the overall impact of pests, by reducing or preventing infestations and making things less “pest-friendly”.

  • Start clean – Insect pests can, and will, arrive under their own power.  Some walk.  Some crawl.  Lots fly.  Others catch a ride.  However, bringing them into your garden seems a bit foolish and is a bit like tempting fate.  It is kind of like saying “They probably won’t like it here”.  Therefore, the strategy is to ensure that any plants that you introduce to your garden are free from insects or other pests.  Give the plants you are buying a good once-over and pick those without any stowaways.  Also, make sure that any plant material that you plant is healthy, so they have a good head start on life. 
  •  Know your friends – There are many (a huge number) beneficial insects running, flying or crawling through the garden.  Try to understand what the insects that are present are doing.  Recognize the insects that that aren’t doing any damage or that might be helping out.  Just because it is on the plant, doesn’t mean it is hurting it.  Some good insects may resemble the bad ones, but you can often tell friend from foe using the statement in the Bible that said “Wherefore by their fruits, ye shall know them.”  Watch what they are doing. You’ll see the clues.

  • Know (and understand) your foe – Just like knowing your friends is important, you have to be aware of the different pests that can damage your plants (a.k.a. your enemies).  Know that what they and their damage looks like, as well as a bit about their life cycle.  This way, you can know whether you have a problem or not and how best to minimize their impact.  The idea is to know what their Achilles heel is and where to hit them.  By knowing how they move, how they overwinter, how they reproduce, if they need specific hosts, what climatic conditions they prefer, you’ll be better equipped to counter them.

  • Encourage rivalries – Once you know friend from foe, you should consider encouraging and/or introducing beneficial insects as a way to manage the problem insects.  You can do this by being judicious in your pesticide applications, planting species that serve as a “home” for the beneficial insects and implement practices that encourage them to stay.  Sometimes you have to sacrifice a bit of quality and a small pest problem to keep your beneficial alive and productive.

·         Exclusion – Some plants can be protected by keeping the pests off.  Essentially, you tolerate them in the neighbourhood, but you don’t let them live on your plants.  It is important to understand the habits and life cycles of the pests you might encounter.  Depending on the pest, you might protect using plant covers, short mesh screens (for those insects that are low flying), barriers around the base of the plants or other means of keeping insects from either feeding on or laying their eggs on or around the host plant.

  • Lure and trap the scoundrels – If you can’t beat them in a direct and fair fight, trick them, then destroy them.  Many insects are drawn to plants by detecting the unique chemical “odours” put out by the plants.  Others are drawn by colour or other triggers.  Use this natural habit to your advantage.  Try the following:

o   Putt out trap plants – these plants serve as sacrificial lambs, which you either drop the bomb on or that you remove once they are loaded (or they just load up on the pests, while the plants you actually like pass unscathed.
o   Place sticky traps - these yellow or blue cards are meant for monitoring, but they catch a fair number of pests, as a side benefit.  They are simple, cheap and just need a bit of sticky stuff to be effective.  Their orientation relative to the ground and their height relative to the canopy will determine what you catch.  Change them when they start to fill up.
o   Place baits (liquid or solid) – these are geared to drawing the pests to where you can either remove them or kill them.  Some people use shallow pans of a beverage or maybe a partially buried piece of potato, depending on the pest.  You might need to change or “recharge” them occasionally, if they are popular.

  • Remove and destroy – Some pests are big enough or occur in dense enough populations that you can pick them up and remove them (and perhaps the plant part that they are on) easily.  Anything that you can do to interrupt their life cycle and cut down the population, the better off you’ll be.  This method ties in nicely to trap plants or baits.  In lots of cases, you need to go after either eggs, adults, nymphs or other immature stages, such as larvae.  I still remember the Great Potato Beetle Hunt of ’85, where a bounty was offered for adults and larvae in a jar and for crushed egg groups. What I don't remember is being paid...

The overall message is that you can have healthy, good quality plants in your yard and garden.  You just have to take steps to accept, encourage, recognize and exclude and with some mental and physical exertion, you should make out fine.