Organic pest control in the garden

Posted: Tuesday 27 May 2014
by Adam Pasco

...although it’s often tempting to reach for an insecticide spray at the first sign of an infestation, I prefer encouraging a natural balance in my garden.

An early start to the season with warm weather through April and May has really given growth a boost. I know commercial rose nurseries always have blooms at the RHS Chelsea Flower Show, but in my East Midlands garden I usually have to wait until much later in June for the first flowers.

Not this year. Fat flower buds are bursting open on many bushes, and I’ve just cut some deliciously fragrant flowers to bring indoors from ‘Golden Celebration’ – a fragrant English rose bred by David Austin.

But I’m not the only one enjoying this new growth. The greenfly and other aphids are loving it too! Soft shoots and sappy growth provide the perfect feeding ground for aphids, and in warm weather one aphid soon gives birth to more, until shoots are coated in ever-growing colonies of the pesky things.

I have seen one of two ladybirds around, so I know they’ll soon be breeding, and both adults and their larvae with their insatiable appetite for aphids will help provide natural pest control. Without pests there won’t be anything for these natural predators to eat, so although it’s often tempting to reach for an insecticide spray at the first sign of an infestation I prefer encouraging a natural balance in my garden.

And balance is the operative word, as pest and predator go hand in hand. So much of the wildlife we try and encourage into our gardens feeds on home-grown pests – caterpillars for the nesting bluetits to feed their chicks, slugs for the frogs and toads, snails for the song thrush, and so on. Patience is required as it does take a while for this balance to be reached, and some plant damage has to be tolerated, but in a wildlife garden that’s only to be expected.

Of course, not every pest has a natural predator either. Sawfly can completely defoliate a gooseberry bush or Solomon’s seal in a couple of weeks, lily beetle devour leaves and flower buds, and woolly aphid coat the stems of apple trees. For these pests I’m always vigilant, and take prompt action to remove them.

Hoverflies will soon be seen around the garden too, with adults feeding on pollen and nectar from broad, open flowers. They’ll soon breed and lay eggs on ornamental plants, fruit and crops, and their tiny larvae will then help out by feeding on aphids.

Achieving a natural balance requires slightly more than a ‘live and let live’ mentality. Where large greenfly or blackfly colonies develop with no signs of predators I do sometimes resort to rubbing pests away between finger and thumb. It helps to do this using a flow of water from a hose, washing away pests in the process. And I’ve an assortment of other things to help keep plants healthy including netting and fleece to protect crops, and pheromone traps to hang in my fruit trees to control codling moth and plum moth.

For now I’m just enjoying the moment, and the fragrance from those cut roses. What a wonderful start to summer!

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Talkback: Organic pest control in the garden
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Felicity Jones 27/05/2014 at 17:57

Woodlice are eating the ripe strawberries in the greenhouse. How can I get rid of them?

philippa smith2 27/05/2014 at 18:03

Check for other predators..........slugs, snails ?  The woodlice usually  come later to clean up what someone else has started

herbgarden2 28/05/2014 at 13:26

So true all you say I also use a brand of bio washing up liquid strongly diluted to spray the flowers if the natural helpers haven't got there yet
It to

Adam Pasco 28/05/2014 at 13:43

Hi Felicity. Yes, the others are quite right that woodlice don't usually cause damage to fruit unless it has been damaged first by another pest to give them access.

If plants are in pots, do raise these up or stand them on staging.

Where plants are growing in border soil take measures to prevent fruit trailing on the ground, and avoid them getting soiled or attacked by pests. Tie developing fruit stems to short canes to hold fruit above the canopy of foliage.

Hope this helps.

Felicity Jones 28/05/2014 at 14:53

Thank you all. I'll try washing up liquid and tie up fruit.