THERE be bugs in the garden.
But that's a good thing, so stay calm, do some homework and understand if you need to intervene or not. Most pest and disease problems result from the wrong plant in the wrong place, too much fertilizer, poor soil and no mulch or poor plant selection. But society's 60-year reliance on the antiquated belief that chemical controls will solve all our P&D problems has left us with not one single insect pest or plant disease being eradicated and an explosion of P&D's that are resistant to pesticides. So here's some simple advice to use when controlling P&D problems in the garden.
To sustainably control P&D problems there are four basic steps to follow: proper identification of the problem; diagnosis of the severity of the problem; implementation of integrated controls, and monitoring and followup.
If you cannot identify the pest or disease accurately then no control will work effectively. Today there are so many books, Internet resources and gardening professionals available that everyone should be able to accurately identify the P&D problem, even if more than one source or opinion is required.
Understanding simple pest identification techniques like weevils notch the edge of the leaf, slugs rasp holes in leaves and caterpillars eat the leaf all the way to the vein, or knowing that powdery mildew is caused by poor plant placement and a dry root condition, can drastically help with choosing the proper control method. So the wisdom is: understand and identify the problem before you act.
Diagnosing the severity of the P&D occurrence requires perspective for gardeners. The outdated and unsustainable standards of no blemishes on my apple, no notches on the leaves of my rhododendron and one aphid is one too many, must be
removed from our thinking if we are ever to sustainably control P&D problems.
Diagnosing also includes understanding whether the pest damage is new this year or from last year. Pests grow in cycles so last year's problem may not be this year's problem. We need to relearn the reality that insects are a necessary part of the garden's long term health. Instead, we have been brainwashed to believe that all insects are bad and must be eradicated - a foolish, arrogant and unsustainable belief system.
Let's look at aphids as a case study in diagnosing the severity of a P&D problem. Aphids are very important food sources for hover flies, lacewings, ladybugs, parasitic wasps and other beneficial insects.
Once a few aphids are noticed on our plants we rush to spray them with pesticides, which will kill the aphids and all of the beneficial insects that naturally control aphids. And so we kill the aphid, their predators and we remove any future food sources for new beneficial insects which collapses the natural predator and prey balance in the garden. The imbalanced insect ecology is made worse by our mind-conditioning addiction to the instant gratification of chemical control methods while forgoing all other methods. The truth is that 15 or 20 aphids are a good thing in the garden, they are "fodder for the goose" and necessary food sources for predatory insects that will eat them.
The wisdom is: a few insects are necessary and unless significant damage is occurring, be patient, have some tolerance and wait to see if beneficial insects will come to dine. Once beneficials start their work, do not intervene and allow the beneficials to reproduce and begin living in your garden. Then and only then will you have long-term control. Control of many pests or diseases is not always that easy but the philosophy is sound and it requires a new perspective to be successful.
The application of integrated controls, using more than one control method at a time is very important if effective control is to be achieved. For example, placing traps, applying Tanglefoot and eliminating fertilizer applications on rhododendrons will achieve far better control than simply spraying a poisonous pesticide that may not work. Traps catch adult weevils, Tanglefoot prevents weevils from climbing the stem and eliminating fertilizer prevents soft leaf growth, thereby preventing weevil infestation on three fronts; hence, a greater measure of control is achieved. The wisdom is: implement multiple control methods simultaneously to achieve effective P&D control.
And lastly, monitoring the effectiveness of control methods provides important information to help better treat future P&D problems. If you do not know how well a given control method worked, how can the control method be trusted in future? Ultimately, sustainable P&D control involves understanding the problem accurately, having some tolerance and patience to allow time for integrated controls to work and adopting the perspective of balance, to allow life to ebb and flow.
Todd Major is a journeyman horticulturist, garden designer, consultant and organic advocate. For advice contact him at [email protected].
