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If you are looking for gardening advice, tips and solutions, use McGregor’s Help Shed for answers to all your gardening questions. The smallest and simplest tricks can make all the difference in your garden. Use the ‘Ask a question’ tool to submit your own questions for our gardening experts.

Latest Questions & Answers

Can I save my Black Spot infected plant?

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Black spot affects roses, iris and other ornamentals. Can cause leaf drop but won’t kill the host plant. Remove infected leaves from plant and around the base and avoid wetting foliage. Spray with Bordeaux mixture and lime sulphar…

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Does treating Rust in Summer and Winter differ?

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Rust is common on roses, broad beans, alliums and ornamentals; it is best to buy resistant varieties. Make sure to dispose of infected leaves, avoid watering foliage and don’t overuse high-nitrogen fertiliser. Spray with Neem Oil in summer or organic Lime…

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Does Verrucosis make fruit inedible? And how can I treat it?

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Citrus scab covers the skin with warty marks. Damage is mainly cosmetic, flavour and juiciness being unaffected. Dispose of fallen leaves from infected fruit (not in compost). Prune trees with an open centre to increase air movement. Spray with copper…

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How can I avoid Powdery Mildew on my plants?

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Reduce by siting plants in well-ventilated places. Remove infected crops in autumn so spores don’t grow over winter. Spray before symptoms appear with milk and baking soda.…

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How can I prevent a white fungal growth on the base of my onion bulbs?

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A white fungal growth on the base of onion bulbs is a sign of the disease called white rot. This fungus affects onions, and leeks, but is less common on chives, garlic and shallots. The leaves of the onion become yellow, die back…

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How can I prevent a white fungal growth on the base of my onion bulbs?

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A white fungal growth on the base of onion bulbs is a sign of the disease called white rot. This fungus affects onions, and leeks, but is less common on chives, garlic and shallots. The leaves of the onion become yellow, die back…

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How can I treat Brown Rot?

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Strikes when stone fruit are nearly ripe and spreads rapidly. Salvage the crop, cut out the bad bits and cook or freeze. Remove all trace of diseased fruit from the tree. Spray with copper in winter to kill the spores. Repeat copper spray just before bud…

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How do I stop host plants dying from Phytophthora infection?

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Root rot caused by fungi can kill host plants (grapes, trees, apples, and tomatoes, heather). Roots die back and whole branches may collapse. Progress may be slow as trees lose limbs over several years. Cut away infected material. Site new plantings on…

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How do I treat Sooty Mould?

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A black fungus layer that grows on the excretions of sap-sucking insects and can decrease photosynthesis of the leaves. Find and treat the offending insects with Neem or an oil spray. Wash sooty mould off small plants with tepid, soapy water.…

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My seedlings were growing well until all of a sudden they toppled over at the base, why did this happen?

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When the stem of young seedlings become withered and topple over, they have probably been killed by a soil-borne fungus called “damping off”. This fungus is difficult to eradicate once it is present in the soil, but you can avoid it by using a sterile,…

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What are the symptoms of Blight? And can I avoid my plants getting it?

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Blight thrives in warm, humid weather. Leaves turn brown and spread rapidly up the plant, which may collapse. Grow tomatoes inside to keep leaves dry, water at the base. Remove and burn infected leaves and rotate crops. Use copper-based spray such as copper…

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What is Leaf Curl? And how can I treat it?

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Peaches and nectarines with red, blistered and curled leaves are showing signs of leaf curl, which can debilitate the tree. Pick off the worst leaves. Spray with a fungus control liquid every week or two during spring (except during blossoming) until all…

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What is the most effective treatment to control thistles whilst not killing my lawn?

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There are several species of thistle that are weeds in New Zealand; Nodding Thistle, California Thistle, Scotch Thistle and Sow Thistle. Californian Thistle is a perennial and can be difficult to control due to vegetative growth from its creeping and spreading root system. In mown lawns it…

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