The RHS’s chief horticultural adviser Guy Barter busts a few gardening myths.
If you think ivy kills trees, watering scorches leaves and digging is always needed to control weeds, think again.
The Royal Horticultural Society is putting the record straight on a number of old wives’ tales which have worked their way into the gardening psyche.
Here, Guy Barter, RHS chief horticultural adviser, busts some of the most popular myths.
• Myth: Ivy kills trees.
Guy says: “Ivy is thought to seldom kill trees of itself, but its presence indicates the very strong suspicion of root disease especially honey fungus doing serious harm to the host and allowing the ivy to flourish under the diminished canopy.”
• Myth: Wild flowers are easy.
Guy says: “Gardens are often just too rich and fertile for wild flowers so that the desirable flowers fade away and rampant grasses take over. Mixes of annual flowers that resemble wild flowers on the other hand are easy and highly beneficial to many insects and a wiser choice for fertile gardens.”
• Myth: Water drops on leaves cause burning from the sun’s rays.
Guy says: “To focus sunlight, a water droplet needs to be above the leaf, and this can very occasionally happen with hairy-leaved plants but in almost all cases scorching is not caused by wet leaves. Spraying leaves with pesticides or liquid fertiliser in sunny conditions can cause harm as the water evaporates and the chemicals become concentrated.”
• Myth: Ground cover plants save work.
Guy says: “Depending on the type of plant you use, ground cover plants can soon become so thick that laborious pruning and thinning is required. Sooner or later perennial weeds set up camp in ground cover and have to be winkled-out by hand as weedkillers and hoes cannot be used. Around trees and shrubs ground cover acts as a particularly pernicious ‘weed’ unless carefully controlled.”
• Myth: Digging is required to control weeds.
Guy says: “The main reason for digging weeds is control, as burial of weeds is highly effective. But if weeds are controlled by other means, such as mulches, herbicides or shallow hoeing, digging can be dispensed with. The only fly in this ointment is that sometimes weed control by other means can take longer and be harder work than digging, so it is not necessarily true for every site.”•
Myth: Raised beds are best for growing crops.
Guy says: “Raised beds are a great idea for badly drained clay soils in wet regions where they enhance drainage and help avoid compaction by trampling. But on other soils they greatly increase drought susceptibility.”