The bluffer’s guide to plant feed
The huge range of fertilisers and plant foods available can be confusing and daunting. So how do you make the right choice?
Whatever you’re growing, we talk you through the options and share the secrets of success
WHEN TO FEED?
Autumn supplements of feed run the risk of encouraging new growth that can be damaged or killed off by winter cold. And there’s no point wasting food on dormant plants that won’t take advantage of extra nutrients. Summer growth plus fruiting and flowering takes it out of plants and they usually require monthly top-up feeding through the summer to keep them at their best.
It’s best to wait for the garden to start waking up in late February before applying feed to help kick-start your plants growing again.
WHICH NUTRIENTS?
The first thing to look for on a plant label is the nutrient balance. The main components of most fertilisers are nitrogen, phosphorus and potassium, which are labelled as ‘NPK’. Plants that are grown for their leaves, such as ornamental foliage shrubs and leafy veggies, require nitrogen (N), so Sulphate of Ammonia would be a go-to fertiliser here. For strong root development, you need a feed that is rich in phosphorus (P), which can be found in bonemeal. Potassium (K) boosts flowers and crops and is in liquid feeds such as Tomorite.
Established trees and shrubs
in the ground need fewer supplementary nutrients than their young and containergrowing counterparts, as their roots have the spread to source the nourishment and water they need.
Newly planted trees and shrubs will need extra water while they put down roots and get established. Fork in a general-purpose granular fertiliser that will break down slowly, then water it in.
Trees and shrubs growing in containers need monthly feeding, as their confinement only provides a limited supply of nutrients. Feed, water and top-dress their pots with well-rotted compost or farmyard manure.
Herbaceous perennials
can be given the same treatment to promote healthy growth and strong flowering. Mulching with well-rotted organic matter slowly releases goodness into the soil, retains moisture and keeps weeds at bay. Only mulch damp soil, as dry soil can form a hard crust that repels subsequent waterings.
House plants – container-grown plants have a limited supply of nutrients, so it’s important to keep them topped up regularly so they stay healthy.
ORGANIC OPTIONS
If you’re looking for fertilisers as an organic gardener, always go for products made of something from a source of nature (an animal or plant). They will be rich in trace elements, which are important for plant health and growth.
Organic products include mulches and enrichers such as shredded bark, garden compost and farmyard manure, as well as more weighty products such as bone meal, blood, fish and bone, plus seaweed extract.