Little time to twiddle green thumbs

By Meg Liptrot

Meg Liptrot's early summer tasks will keep gardens on track.

Meg's father John Liptrot prepares to shorten a grapevine and cut off any unproductive dead wood. Photo / Meg Liptrot
Meg's father John Liptrot prepares to shorten a grapevine and cut off any unproductive dead wood. Photo / Meg Liptrot

The beauty of the cooler months is that almost everything in the garden stays as you left it. Not so in spring and summer, when the garden is roaring along at breakneck speed - blink and the hedge has grown dreads.

This October was hotter in Auckland than the average and it was drier than usual, too. Niwa's rainfall projection for the North Island for October to December is "normal or above normal".

This weather has provided perfect conditions for bugs such as whitefly to proliferate. Our orange tree already has significant numbers and summer has only just officially begun.

Before these and other summer garden pests and diseases get out of hand, there are a few techniques that will keep population numbers in check.

Here are some tips to help keep your garden in shape.

Invasion of the suckers

Use yellow sticky traps to catch the first onslaught of whiteflies and assess numbers (or check under leaves). Hang pheromone traps in apple trees to catch male codling moths before they get to females. Their larvae tunnel into apples, spoiling the crop.

•Biological pest management tools are available through Bioforce (www.bioforce.net.nz). The "Enforce" cards have tiny wasp pupae on them - a species called Encarsia formosa - which parasitise whiteflies. Just hang in the affected plant and let nature go to work. This technique is mainly used in greenhouses. Bioforce also supplies dusky ladybirds, whose larvae predate on aphids.

•Plant your garden with a range of beneficial insect plants such as phacelia, chamomile and alyssum to encourage the good bugs. Plant cleome to distract shield beetles from your tomatoes and beans.

•Organic sprays, which include soapy potassium fatty acids, are effective against small-bodied insects including aphids, whiteflies, thrips, mites and passionvine hopper nymphs. Ensure you saturate the undersides of leaves. Spraying neem oil every couple of weeks will also reduce pest numbers. Apply sprays in the evening, but avoid spraying too much if you have employed the services of beneficial insects.

Fungal foes

Anticipate fungal attack by getting in early. Simple preventive measures avoid the unnecessary use of heavy chemicals later in the season.

•Roses respond well to the regular foliar spraying of seaweed solution every couple of weeks for general health and to reduce the occurrence of blackspot. Spraying every 10 days with diluted milk (40:60 ratio milk to water), is also known to work on mildew-prone plants such as roses, grapes, apples, courgettes, cucumbers and pumpkins.

•Increase airflow in your garden by thinning summer growth on shrubs and trees. This will reduce fungal issues on plants by reducing humidity.

Trimmed and tidyTrim hedges if they're shaggy and ensure the base of the hedge is a little wider than the top. That way, light can reach the lower parts of the hedge.

•Spring-flowering shrubs can be pruned now after flowering. Prune for shape and airflow and remove any old or dead wood.

•Regularly deadhead repeat-flowering roses to keep blooms coming.

Fruit

If you've neglected to prune your grapes or berryfruit, now is a great time to cut off any unproductive dead wood and shorten vines, as you can see clearly what is healthy and what's not. Once baby grape bunches form, shorten the vine to a few leaf nodes past the bunch. This way, the vine is not expending its energy on unnecessary growth, and airflow and light is increased to keep the grapes developing well. The leaves will keep the grapes out of sight of birds.

•Feed citrus trees with rich compost or manure, or spread potassium-rich comfrey leaves or water with comfrey tea, then mulch.

Salad

All the heat-loving summer veges such as tomatoes, eggplants, cucumbers, courgettes, corn, beans and greens can be planted now. Get young plants growing strongly with weekly applications of diluted compost tea, vermiliquid or liquid seaweed. The soil has dried out significantly already, so it pays to water every couple of days if need be. Do the finger test to check soil moisture 5cm down before watering, ideally in the morning or evening.

•Net young seedlings to protect from blackbirds.

•Make use of the sun on a hot day and hoe young weeds before they get deep roots. Let the weeds desiccate on the soil surface where they will break down, adding organic matter to the soil.

Quench the thirst

If this summer turns out to be as dry as last year, we need to get mulching now. Wait until there's been a couple of days of decent rain, then pile on the mulch in border gardens. Don't mulch against tree trunks as this will likely cause its bark to rot.

•Catch it while you can - it's not too late to put in a rain barrel or three.

- NZ Herald

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