Fruit trees: feeding and mulching
Feeding fruit trees promotes healthy growth, giving the plant all the nutrients it needs to produce the best possible crop. Mulching helps conserve moisture in summer and prevents weeds from growing.
Timing Feeding: late winter or early spring. Mulching: mid- to late spring and autumn
Most fruit trees need high amounts of potassium, which is essential for bud and fruit development. Some fruits, such as stone fruits, pears and culinary apples, require additional nitrogen for growth.
The ideal time to plant fruit trees is in the autumn, but container grown plants can be purchased at garden centres and planted at any time of the year provided the soil is not frozen, waterlogged or extremely dry.
When to feed fruit
Carry out in late winter or early spring in preparation for the growing season.
Apply mulch in mid-to-late spring and autumn. Newly planted fruit trees should be mulched annually for the first three or four years with bulky organic matter to conserve moisture and reduce competition from weeds and grass. However, mulches contain very few nutrients compared to fertilisers so are not an alternative but complimentary.
Bulky organic matter includes the following options:
How to feed fruit
Fertilisers are concentrated sources of plant nutrients. They feed plants rather than feeding the soil. Fruit trees benefit from regular fertiliser. There are many types of fertiliser available, all with different nutrient values.
- Make sure that the soil is moist – late winter or early spring is best
- If the tree is growing in grass, it is best to remove a 1m (3¼ft) wide ring from around the base and lightly forking over the soil before feeding
- Sprinkle the fertiliser over the tree's rooting area (that is the area just beyond the branch canopy). Moderate the quantities given if the trees are growing vigorously
Three main elements are needed for plant growth: nitrogen (N) to encourage good growth, phosphorus (P) for root growth and potassium (K) for fruit and flowers.
Apples and young pear trees
Apples and young pear trees need nitrogen fertiliser annually, with culinary apples requiring more nitrogen than dessert varieties. To put this theory into practice, simply choose any one of the methods below. And, for dessert apples, apply an additional 25g per sq m (¾oz per sq yd) of sulphate of potash every three years.
Method one: Each year, use a potassium-rich general fertiliser (rose fertiliser for example) in late winter as directed by the manufacturer.
Method two: Each year, use Growmore fertiliser. Apply 100g per sq m (3oz per sq yd) for dessert apples in bare soil and 140g per sq m (4oz per sq yd) for dessert apples in grass. For cooking apples, use 50 percent more.
Method three (organic alternative): Use the weights stated in method two, but substitute Growmore with dried poultry manure pellets. Organic potassium (instead of sulphate of potash) can be used every three years.
Pears (established), cherries, plums, gages, damsons and peaches
- These fruits need a balanced general fertiliser in early spring. As a result, sprinkle Growmore around the root zone at the rate of 140g per sq m (4oz per sq yd)
- Organic growers can use similar amounts of dried poultry manure pellets with some organic potassium every three years
It is worth noting that occasional soil testing is helpful in ensuring feeding regimes are effective. Testing every four years is sufficient. Click on the link for the service offered by the RHS.
Fruit trees in containers
When growing fruit trees in containers a slightly different approach is needed.
How to mulch fruit
Organic (biodegradable) mulches improve soil structure and fertility as they are drawn down into the surface layer by earthworms.
- Make sure the soil around the tree is thoroughly moist (but not sodden) before applying the mulch. Late winter is the ideal time to mulch
- Spread the mulch 7.5-10cm (3-4in) deep around the base of the tree to cover the rootball area
- Keep a mulch-free circle around the base of the tree trunk (about 7.3-10cm or 3-4in) to prevent the bark decaying
Inorganic (non-biodegradable) mulches do not improve the fertility or structure of the soil, but they do suppress weeds and conserve moisture. Shingle, pebbles, gravel, and other decorative aggregates can be used around trees. Permeable woven landscape fabrics can also be used that allow rain and irrigation water to reach the roots. Note that light coloured mulches reflect light back into the canopy which is particularly valuable for cherries.
- Some mulches can be unsightly or troublesome when it is scattered by foraging birds
- All mulches provide refuge for slugs and some types are a refuge for snails
- If mulches are laid in direct contact with the tree stem they can cause it to soften, making it vulnerable to disease
- A build-up of mulch can produce a hard layer, which is difficult for water to penetrate. Avoid this by only replacing mulch when it has rotted away or fork the remaining mulch into the soil
Magnesium deficiency is the most common problem. The main symptom is a yellowing between the leaf veins in early summer (more commonly seen in thin soils and regions with high rainfall). It can be rectified by spraying with magnesium sulphate (Epsom salts) as a foliar spray at the rate of 226g to 11.5 litres (8oz to 2½ gallon) of water. Using a wetting agent (half a teaspoon of washing up liquid) improves the effectiveness of spraying. Magnesium sulphate could be applied direct to the soil if the problem regularly occurs. Apply at a rate of 65g per sq m (2oz per sq yd) in mid-spring. Apples and peaches are particularly prone to this nutrient deficiency.
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