We're all familiar with the concept of spring cleaning – shaking off the old, dusting down the decks and freshening things up. When it comes to fruit trees a more accurate description would be 'winter cleaning', as this is the time of year when we draw a line under the past year and look ahead to the next. It's our opportunity to get on top of bothersome weeds and lurking pests, check that trees are growing unhindered, and generally prepare the ground for another stellar season of fruitful rewards.
Weed and Feed
The first task to tick off the job list is a spot of weeding. Removing weeds from the base of fruit trees not only eliminates competition, it removes hiding places for insect pests that might be trying their luck by overwintering. Move weeds to the compost heap then fork over the ground to fluff up the soil. This will expose any grubs and eggs to hungry birds and the cleansing effects of frost.
Later on in winter you can fork some general-purpose organic fertilizer into the soil before applying a fresh layer of mulch. But it is important to wait until the worst of winter is over so that cold snaps have had a chance to work their pest-clearing magic. Thick mulches laid 5cm (2in) thick will slow down the progress of new weeds, lock in soil moisture, then help to gently feed and improve the structure of your soil as they rot down into it.
Eliminate Overwintering Pests
Overwintering insects and their eggs are a common cause for concern in the fruit garden. The likes of aphids, red spider mite, scale insects and codling moth grubs can sit out winter by tucking themselves into the tiniest of nooks and crannies found within a tree's bark. They'll then rear their unwanted heads in spring as soon as warmth returns. Early winter is your chance to scupper their plans by spraying a winter tree wash onto your dormant trees. A repeat spray can be applied at the end of winter.
This natural, plant oil-based treatment is highly effective at dramatically reducing pest numbers. It is safe around pets and children, and by applying it at this time of year it will have minimal impact on other wildlife. Spray it directly onto the bark on a still, windless day, covering all of the branchwork to leave no escape. Don't forget to wear a mask and gloves to protect yourself from drifting spray.
Another preventative pest defence is the glue band, which stops egg-carrying moths from climbing up into the tree's branches from ground level. Tie the sticky bands securely around the trunk of each tree, glue-side facing outwards. Use string at the top and the bottom of the band to give a really tight fit so that the moths can't climb up beneath it. Apply bands to stakes as well – you don't want these acting as bridges to the destructive moths.
Keep Stored Fruit Healthy
With all the leaves long shed it's easier to spot and promptly remove any mummified fruit hanging on in the branches. You may think these fruits pose little threat, but they are carriers for disease; left on the tree they have the potential to re-infect the following year. Better safe than sorry, so you're best rid of them.
Fruit stores will need regular check-ups to identify the first signs of rot or pest damage. Check through fruits at least once a week. Soft fruit should be used up or thrown onto the lawn for ground-feeding birds. The old adage of one spoilt apple upsetting the apple cart is all too true. Due vigilance will ensure you keep on top of rotting fruit so that the remainder stays in good order. If mice or other small animals have raided fruit stores then make sure the perimeter to your store is properly secure and block up any gaps.
Cold Weather Protection for Fruit Trees
While cold weather is fantastic at finishing off hibernating pests, it can play havoc with vulnerable plants in pots. Ensure that semi-hardy fruit trees such as olives and lemons are moved into the protection of a greenhouse or cool conservatory if they haven't been already. Fleece jackets are available for hardier specimens, or make your own by wrapping garden fleece around branchwork and packing in additional straw for further insulation. Trees in pots also need proper drainage because sodden roots spell disaster when they freeze solid in prolonged cold weather.
Large dumps of snow are heavy, potentially weighing down branches to the point of snapping. Knock off snow using a broom or shake it free – but gently, as cold wood is brittle.
Repeated frost-thaw cycles can unsettle recently planted trees, loosening the roots and making trees susceptible to wind damage. Autumn winds can also loosen supporting stakes, leading to an inevitable wobble. Check stakes after frosty weather and firm trees back in as necessary.
Winter is also the time to replace rotten stakes, broken supporting wires on which wall-trained fruits are growing, and frayed tree ties. Stems and trunks swell as they grow, so existing tree ties may need loosening to prevent them digging into the bark or rubbing it and opening the door to fungal infection.
So there's plenty to be getting on with as winter bites. No excuses for sitting idle! As if you needed encouragement – an afternoon spent working on your fruit trees is satisfying to the core. The promise of next year's fruits should soften the chill and warm the spirit.
By Benedict Vanheems.
Grease band photo courtesy of Harrod Horticultural