WHAT TO DO IN THE GARDEN THIS WEEK

Last year I lost the bulk of my apple and pear crop to codling moths. I don’t know what else to do. In the first year of moving into our house we had little problem, then it grew steadily worse. I’m at the point of cutting down my trees. Do you have any advice on how to rid my garden of this destructive beast.

Christiaan Van Noppen, Pt Chevalier

Answer: Codling moth caterpillars are creatures that eat your apple cores and leave brown exit holes.

Probably the most common pest in the orchard, Cydia pomonella infects all pip fruit and walnuts, and can cause considerable damage.

The following describes the pest’s life cycle – and my strategy for dealing with it.

Winter: caterpillars are cocooned in hidey holes. Remove all fruit, leaves and growth around trees – anywhere pupae may be hidden. Scrub trunks with a stiff brush and clean..

Spring when in full bloom: adults emerge, mate and lay eggs once temperature is over 15°C. Use traps to determine when this happens – leave them out as there will be another generation. Pheromone traps attract males; they do nothing to reduce breeding but are an indication of numbers and will tell you when to spray. Pheromone mating disrupters can also be used in spring.

Late spring, about petal fall: larvae hatch and burrow into fruit. Hit the caterpillars with spray before they disappear into the fruit. I use Madex 3, Cydia pomonella granulovirus. It is highly specific to the codling moth and organic. At about $125 for 100ml, it’s not cheap, and one bottle is enough for a whole hectare.

A cheaper option is Kiwicare Organic Caterpillar Bio control. Though not sold for codling moth – its targets are pests such as leaf roller, white butterfly and looper – the Bacillus thuringiensis it contains is effective against the codling caterpillar. Both Madex 3 and the Kiwicare product are only effective against the larvae before it enters the fruit.

At this stage, oil sprays may also be effective in smothering the eggs, and garlic or pyrethrum sprays can be used against the adult moths, though these will also be detrimental to beneficial insects, including pollinating bees.

Repeat spray at 5-8 day intervals until four weeks after you no longer find adults in the traps.

Caterpillars feed in fruit then look for crevices to cocoon in. I tightly wind corrugated cardboard around branches and trunks, and circle below with grease. This will force any caterpillars to cocoon in the cardboard. Be sure to remove and check to monitor numbers. Keep traps out – and sticky – and monitor until numbers cease in March. Replenish milk-bottle traps as needed. Spray 10 days after traps indicate adults are on wing.

All you need is love

November continues to be an exciting and busy planting time for us in the garden and, no doubt, there are a few obstacles we’re all having to overcome. It gets to the point sometimes where you want to throw your arms in the air and ask what next? But as mum used to say; “never give up, get out there and try again, you can do it”. Gardening teaches resilience.

The weeds are growing out of control at our place and as soon as I pull one crop, another two appear. A big weeding effort is going on at home and I tend to do a little each night after work. The weekend is when I really get stuck in.

Snails and slugs are a bugbear at the moment, easily treated with a heavy foot and poisonous pellet baits. And I’m keeping a keen eye out for moths, thrips, whitefly and aphids. I expect these to become more of an issue as temperatures climb.

Best advice from several far more experienced and worldly gardeners has been to step back, take a deep breath and sit down in the garden with a cup of tea. Then formulate a plan of attack. Right now I just want to plant greens and ignore everything else.

As NZ Gardener editor Jo McCarroll says: “When there’s so much you can sow and plant, the challenge is holding back…a successive approach of little and often is a better idea than packing all your available growing space with vegetables that will be ready at once.”

So here’s what I’m going to do. First task will be to replant dog damaged crops, especially silver beet, spinach, lettuces, Asian greens and rocket, which are long-standing staples in our house. I’ll also replace the basil and mint, which always go well with tomatoes, and the capsicum and chillies.

This year I’m going to be a little more adventurous and plant swedes and eggplants.

Chaotic weather

Windy and wet weather has been causing a few issues for gardeners south of Waikato. Taranaki gardener and academic staff member at Western Institute of Technology, Carl Freeman, says spring is an exciting time because everything grows. But, he says, he’s still holding off planting outside because of the cold, wet, windy weather. “We’re holding off a little longer, maybe a couple of weeks, because of the chaotic weather. It’s a really tempting time to get in the garden but remember summer and autumn go a long time.”

The wind is a particularly tricky issue in Taranaki as the prevailing wind can change depending on where you are around the coast or under the mountain.

Freeman has been growing tomatoes and cucumbers in hothouses and getting some excellent results. He’s putting a lot of effort into improving the soil with worm castings, organic and mineral fertilisers. He’s also mulching heavily to control the temperatures, improve soil quality and retain moisture.

He’s been using raw milk as an antifungal. “We water the leaves with the milk using a 10L watering can.” Cow and goat’s milk have proven to be an effective fungicide in the garden, often better than chemical fungicides at controlling powdery mildew.

Speaking of recycling and pests

Pests are an ongoing problem for all gardeners. And what is beneficial at one point of the year may become a problem later. Take birds for example. Dr Nick Roskruge recommends encouraging birds in the garden, as most fruiting plants and trees are now setting fruit and young vege plants are a magnet for many pests. Unfortunately those same birds may become a pest once the fruit has ripened.

Mrs Gardener is a keen recycler and says we should never throw anything out before thinking about how it can be reused. She recently replaced her white net curtains and suggested I use the old ones to drape over our grape vines and fruit trees when the fruit is near ripe to stop the hungry birds helping themselves.

McCarroll recommends using companion plants to attract predatory insects. Add buckwheat, alyssum and phacelia bring in predators. Trap crops can be used to specifically trap pests you want to target. Try clemone and calendula to attract green vege bugs, nasturtium for aphids, marigolds for nematodes and chervil for slugs.