Gardening – Tackling pests, nature’s way

New subdivisions have flourished on the peninsula recently, bringing in many fledgling gardeners. 

A number have asked me if I would help them plan a practical garden on their sections that are overlaid with many obstacles.

Together we have rearranged play spaces, re-configured paths and decks, and even removed some expensive newly planted display shrubs! 

Children have used their maths skills to help lay out the macrocarpa bed frames, gathered the cardboard to cover the lawn and helped order a truckload of arborists’ mulch, while dad has collected the soil mix so seed raising can be started.

Seaweed, grass clippings and manure have been sourced, along with a visit to the local community garden to see how plants grow. Much diversity is discovered, including weeds and insects.

Suddenly there are questions – ‘how will we tackle the weeds and pests?’, ‘can you recommend a weed killer, a spray?’ 

In the arms race between biology and biotechnology, the weeds are winning. Yet many gardeners cling to the unrealistic idea that chemical companies will invent a miraculous new herbicide. Even if such a miracle product were close at hand, an even greater threat looms large: weeds always adapt to whatever is trying to kill them.

Evidence is mounting that weeds can metabolise herbicides, breaking them down before the herbicides can do their work. 

Globally, 263 species in around 71 countries are known to have evolved resistance to herbicides, encompassing nearly every major class of weedkiller on the market.

Hopefully this demonstrates the value of gardening in harmony with nature to grow our own organic ‘superweeds’, some of which we will eat to continue to build our own metabolic resistance.


Be smarter than the pests

• Make sure you grow in season. • Plant a beneficial insect garden to encourage beneficial insects like parasitic wasps, ladybirds and praying mantis • Warm season crops need temperatures well above 16 degrees, especially at night and if you can’t wait, use row covers to keep them warm. Stressed plants attract insect pests. • Confuse insects by interplanting your vegetables. • Plants have an immune system. Feed it by feeding the soil – make liquid manures with seaweed and comfrey and horse manure. • Make compost and use mulches to build up the soil food web • Dilute liquid manures to use as a pest spray. • Identify the three main pests for summer crops – green shield beetles, aphids, and white butterfly caterpillars. Be able to recognise them on your plants.  Especially the green shield beetle’s egg cases. 

More details on spray free pest control next column.