GRAHAM CLARKE’S WILDLIFE WATCH
How plant food affects wildlife
AS far as garden wildlife is concerned, the best way to feed plants is with homemade leaf-mould and compost. Add occasional amounts of well-rotted animal manure, and the plants and wildlife in your garden, will show their gratitude. But how many of us are able realistically to confine our plant-feeding to these heavy-duty products?
With the best will in the world, it isn’t usually possible to make enough compost or leaf-mould to meet all of our gardening needs. So buying artificial plant foods is the norm but you need to choose and use the products wisely. Sustained use of granular, powdered and liquid fertilisers may increase plant health, prolong flowering and give bigger crops, but it can also alter the biodiversity of a garden.
Bonemeal, for example, is one of the oldest plant foods available. Approved by organic gardeners, it’s a slow-release fertiliser, primarily used as a source of phosphorus for healthy root development. But it is a mix of groundup animal bones and other waste from the slaughter house, and it can encourage foxes, rats, badgers and carrion-eating birds, all keen to sniff out anything that is derived from animals. Watch out, too, for high-nitrogen feeds, such as sulphate of ammonia – used for leafy crops like brassicas and salads. If you apply too much, new growth will be puffed up and succulent, and even more attractive to greenfly than normal.
In spring, all new plant growth is full of juices, and loading on fertilisers will attract aphids like nothing else. Broad beans in a well-maintained vegetable plot will stand out as prime targets, as will roses grown in a carefully weeded bed. However and wherever you apply plant fertilisers, the most important thing is not to allow any run-off into water. If it gets into a garden pond it will cause the growth of algae. This ultimately uses all the oxygen in the water and suffocates all pond life, including aquatic plants.
Arguably the best of the artificial plant foods is tomato fertiliser. High in potash, it’s designed to encourage more tomato flowers, and therefore more fruits. When used on other plants (and it can be used throughout the garden to increase the flowering potential of anything), it will result in more visits from bees, butterflies and other pollinators. So not all fertilisers are bad!