Quick Questions
Will mulching with pine needles make soil more acidic? Claudia Rainer, by email Pine needles have li le effect on soil pH. They’re a good mulching material to keep weeds down, but ensure a layer is at least 6cm (2½in) deep. Sulphur chips will make soil more acidic but it’s not really economic. Be er to grow plants suited to the soil pH.
What small trees will thrive on a windy hill? John Graham, Guildford, Surrey Olives cope well with windy conditions, as does Phillyrea latifolia. Acer campestre, the field maple, is also good for exposed situations with bu er-yellow autumn colour. Euonymus
europaeus ‘Red Cascade’ has brilliant red autumn colour. All can be pruned to keep them compact.
How long will garden pesticides and fungicides last? Andrew Baker, by email Check for a use by date and abide by it. Chemicals stored in conditions of excess heat or cold, or exposed to air, may degrade. As a rule of thumb don’t retain for more than two years. Take out of date chemicals, or those that have had their approval rescinded, to appropriate recycling centres.
Will rose chafer grubs in my compost heap cause a problem? Naomi James, Bridgwater, Somerset Garden and Welsh chafer larvae destroy the roots of turf grasses in lawns, but the rose chafer is considered beneficial as the grubs feed on decaying organic ma er and, in so doing, help the composting process.
The rather pre y adults are 2cm (just under 1in) long, metallic green and feed on pollen and nectar.