How to grow trees

What is a tree?

Trees usually have a single woody trunk, topped with a permanent network of branches. Some are slow-growing, long-term plants that will often live for several decades or more. Others are fast growing, often with shorter lifespans. Some species grow quite large over time, while others stay compact. Many produce attractive flowers and edible or ornamental fruits or cones. Evergreen trees keep their leaves all year, while deciduous

Deciduous refers to plants (mainly trees and shrubs) that lose their leaves seasonally, usually during autumn. This is a natural process triggered by the season's shorter days and lower temperatures and allows plants to conserve energy during the winter months. trees lose their leaves over winter, often after a colourful autumn display.

Choosing the right tree

With such potentially long-lived plants, it’s crucial to choose the right one for your site. Whatever your soil type and local climate, there will be trees that will thrive there. See assessing your garden conditions , as well as our guides to trees (and other plants) for wet soils, sandy soils, clay soils and chalky soil.

Getting the right look

Consider what you want from your tree, such as:

• Size and shape – eventual height and spread are prime considerations, as you’ll be buying quite a small plant that is considerably less than its mature size. Make sure you buy a tree that won’t outgrow your space, block out too much light or cause a nuisance to neighbours. See our guide to trees for small gardens.
• Evergreen or deciduous? Trees that keep their leaves retain a consistent appearance throughout the year. They’re great for winter interest, as well as for blocking out overlooking buildings. Trees that lose their leaves often produce vibrant autumn colour and let more light into the garden in winter. Their appearance changes across the year, marking the different seasons and creating renewed interest.
• Season(s) of interest – do you want flowers, fruits and colourful foliage in spring, summer, autumn or winter, or in several different seasons?
• Shade – do you want a tree with a dense canopy of leaves to provide welcome shade in summer, or would you prefer a small or light canopy that simply filters the sun?
• Flowers and ornamental fruits? Some trees offer spring blossom or catkins, while exotic species may produce more vibrant summer blooms. These may be followed by all manner of interesting and attractive fruits, nuts, berries, cones, winged seeds, pods or spiky seed cases. See our guide to flowering trees for small gardens.
• Edible fruits? Growing your own fruit or nut crop can be really rewarding – see our guide to choosing a fruit tree. Consider more unusual fruits too, like mulberry, quince or medlar.
• Traditional or exotic? Would you like a familiar, traditional garden tree that fits into the surrounding landscape? Or would you prefer something more exotic and unusual, like a palm tree, that will stand out and create a tropical feel? See our guide to native trees.
• Foliage colour – tree leaves come in every shade of green, as well as yellows, reds, blues and silvery-greys. Conifers in particular offer a wide range of hues, which makes them stand out as focal points. See our guide to colourful tree foliage.
• Wildlife-friendliness – many trees offer nectar-rich flowers for insects, and/or fruits, nuts, berries or seeds that attract hungry birds and squirrels. Most trees also offer nesting sites and shelter.
• Instant height or smaller and cheaper? Trees are usually bought when they are still quite small, only about 60-90cm (2-3ft) tall. These settle in well and will soon put on growth. However, if you want instant height and impact, you can buy taller, more mature specimens, although these can be much more expensive and often won’t settle in as quickly or as easily.

Trees and shrubs with attractive bark

Trees and shrubs: variegated foliage

How and what to buy

Trees are available all year round in large containers from garden centres, nurseries and online suppliers. Some, especially fruit trees and other deciduous hedgerow trees, can also be bought as dormant

Dormancy refers to a period of inactivity in plants, during which they slow down or stop their growth, conserving energy and resources. This is a natural process that helps them survive harsh conditions, such as winter or drought. Dormancy in seeds is a mechanism that prevents them germinating until environmental conditions are favourable for growth. bare-root

These have been lifted from the ground while dormant, with little or no soil around their roots. Various plants may be available bare root, including fruit trees, hedging plants and some perennials. They are generally cheaper than plants in containers, but are only available in winter/early spring, while dormant plants in autumn and winter, usually by mail order. Bare-root trees are cheaper, but the choice may be more limited.

Buying: trees and shrubs

Where to get ideas and advice

• Visit gardens and arboretums to see which trees you like best. All RHS Gardens feature plenty of beautiful trees, large and small, and all are labelled, so you can note down your favourites.
• Go to RHS Find a Plant – search for ‘trees’ to browse the photos and plant descriptions, and find out where to buy them. You can refine your search by specifying preferences such as ultimate size and season of interest.
• Ask at local garden centres, which should stock a range of trees that suit your local conditions.

When to plant

The ideal time to plant all trees is between autumn and early spring, whenever your soil isn’t waterlogged

Describes soil or potting compost that is saturated with water. The water displaces air from the spaces between soil particles and plant roots can literally drown, unless they are adapted to growing in waterlogged conditions. Waterlogging is common on poorly drained soil or when heavy soil is compacted. or frozen. Container-grown trees can be planted at any time of year, but avoid planting during hot or dry weather.

Where to plant

Most trees like an open, sunny position, but there are trees to suit all growing conditions. You can even plant some trees against a wall as a fan or espalier.

To get the best crop from fruit trees, you need to plant in a site that suits their individual needs – check out our guide to positioning fruit trees.

Trees that originate in warmer climates may need a sheltered spot, or given winter protection in frost free

Frost-free environments, such as a cool greenhouse or conservatory, have a nighttime minimum of 4°C (39°F). This is ideal for plants tolerant of low temperatures, but will not survive being frozen, such as tender plants being overwintered including pelargoniums; frost-tender rooted cuttings such as penstemon; and bedding plants in spring. conditions such as potted citrus trees. The plant label will tell you how hardy the tree is.

Certain trees prefer acidic soil, such as most magnolias and witch hazels (Hamamelis spp.) and won’t cope if your soil is alkaline. See our advice on identifying your soil type, then check plant labels before buying.

Always plant trees in a position where they will have room to reach their mature size. Plant labels should give details. If your space is limited, there are many small trees available. See our guides to trees for small gardens and cherries for small gardens.

Many smaller trees can be grown in containers – this is especially useful for trees that don’t like British winters, such as citrus, as they can be easily moved into a frost free conservatory or greenhouse during this period. Many miniature forms of fruit trees are available for growing in large containers too. Check out our guides to growing trees in containers and growing fruit in containers.

Bearing in mind that trees can live for many years, with some growing to a large size, make sure you choose a site for your tree where it won’t cause problems in the future. See our advice on trees near buildings and trees and the law.

How to plant

Planting a tree is quick and easy, but worth doing carefully to ensure it settles in well and thrives for years to come.

Check out our selection of tree planting guides, for all you need to know:

• Guide to planting trees
• Beginner’s guide to planting trees
• Step-by-step guide to planting a tree
• Guide to planting apples

Once they have settled in, most trees need very little attention. Fruit trees, however, benefit from regular pruning, while trees in containers need extra watering. Trees from warmer climes, such as citrus and may need protection over winter.

Watering

During the first two years after planting, new trees need thorough watering in dry spells to ensure the water reaches the full depth of the root system. The quantity required will vary with soil type, but would typically be four to six 9L (2 gallon) watering cans each week in dry weather.

Well-established trees which aren't grown for their fruit, generally don’t need to be watered, except in prolonged dry spells. Fruit trees on the other hand need regular access to moisture in order to produce worthwhile crops.

Feeding

Trees don’t need fertiliser in their first growing season, as you want the roots to grow out into the surrounding soil in search of nutrients

To grow well, plants need a wide range of nutrients in various amounts, depending on the individual plant and its stage of growth. The three key nutrients usually taken up from the soil are nitrogen, phosphorus and potassium. Plants also need carbon, oxygen and hydrogen to make carbohydrates — their main energy source. Carbon and oxygen come from the air as carbon dioxide, while hydrogen is drawn from water absorbed by the roots. Other important soil nutrients include magnesium, calcium and sulphur. Most garden soils contain enough of these nutrients to support healthy plant growth. and moisture. This will help them establish a healthy root system and become self-sufficient.

On poor soil, it may be beneficial to feed a tree the year after planting. Apply a balanced, general-purpose feed over the entire root area in spring, at about 70g per square metre (2oz per square yard).

To maximise the crop on fruit trees, annual feeding is recommended – see our guide.

Trees in containers also need feeding, as the nutrients in their compost

Can refer to either home-made garden compost or seed/potting compost: • Garden compost is a soil improver made from decomposed plant waste, usually in a compost bin or heap. It is added to soil to improve its fertility, structure and water-holding capacity. Seed or potting composts are used for growing seedlings or plants in containers - a wide range of commercially produced peat-free composts are available, made from a mix of various ingredients, such as loam, composted bark, coir and sand, although you can mix your own. will soon run out. Check out our guide to container maintenance for full details.

Fertilisers

Weeding

Grass and weeds compete with young trees for water and nutrients in the first five years after planting. If you plant a tree in a lawn, leave a circle at least 90cm (3ft) in diameter without turf, as a covering of plants or turf over the tree’s root area can compete with the tree for nutrients and moisture. This hinders the tree's establishment and subsequent growth.

Guide to controlling weeds

Mulching

It’s best to lay a mulch

Mulch is a layer of material, at least 5cm (2in) thick, applied to the soil surface in late autumn to late winter (Nov-Feb). It is used to provide frost protection, improve plant growth by adding nutrients or increasing organic matter content, reducing water loss from the soil, for decorative purposes and suppressing weeds. Examples include well-rotted garden compost and manure, chipped bark, gravel, grit and slate chippings. of well-rotted manure, garden compost, bark

Bark is the outermost layer of woody plants (trees, shrubs and woody climbers). It is several cells thick and provides protection against physical damage, disease and environmental stresses. Bark comes in a wide variety of colours and patterns, and these can help gardeners when identifying plants. The fissures and crevices of bark on older plants also creates valuable habitat for many garden creatures as well as lichens and small plants. chippings or leafmould around the base of all trees, but particularly newly planted ones. This will suppress weeds, provide nutrients, hold in moisture, improve the soil conditions and support the growth of beneficial mycorrhizal fungi in the soil.

After clearing any weeds, spread a 7.5cm (3in) layer of mulch over the root area, but leave a gap of 10-15cm (4-6in) around the base of the trunk to prevent rot. The ideal time to do this is in late winter, after any fertiliser has been applied, to conserve winter moisture in the soil. Top up the mulch whenever necessary and re-apply every year.

Fruit trees: feeding and mulching

Mulches and mulching

Overwintering

• Hardy trees need no additional winter protection – check plant labels for hardiness before buying.
• Small, early-flowering fruit trees, such as nectarines, need protection if frost is forecast when they’re in blossom. If the flowers are damaged, the future crop will be reduced or destroyed. For full advice, see our guide to protecting fruit from frost.
• Tender trees are best grown in containers, then moved into frost free
  Frost-free environments, such as a cool greenhouse or conservatory, have a nighttime minimum of 4°C (39°F). This is ideal for plants tolerant of low temperatures, but will not survive being frozen, such as tender plants being overwintered including pelargoniums; frost-tender rooted cuttings such as penstemon; and bedding plants in spring. conditions over winter.

Looking after trees in containers

These need additional watering and feeding, and regular repotting into larger containers as they grow.

Container maintenance

Adjusting ties and removing stakes

Inspect tree ties every spring and autumn and adjust any that have become too tight, as they can damage the trunk. After two years, the tree should have made sufficient root growth to anchor itself firmly in the soil and the stake can be removed.

Pruning ornamental trees

After planting a new tree, you can simply leave it to grow as it pleases. However, if you want to ensure it forms a clear trunk with an even, well-balance canopy, you can give it some initial pruning over the first few years – see our guide to formative pruning.

Once the formative pruning is complete, most ornamental trees won’t need regular pruning. However, do check them occasionally for damaged, diseased or dead stems, which should be removed, and for uneven growth or other problems that need remedying. These include:

• Suckers – some trees produce vigorous shoots from the base or below ground, which need to be removed regularly – see our guide to removing suckers.
• Reversion – trees with variegated
  Variegated means having leaves or other plant parts with streaks, blotches or patches of different colours. Typically, these would be a combination of two colours, such as green and gold or green and white. or coloured foliage can sometimes produce vigorous shoots that are plain green. These should be removed before they take over – see our guide to reversion.
• Outgrowing its space – if a tree has grown too large or its canopy is too broad or dense, it is possible to reduce its height, thin out the branches or lift the crown by careful pruning – see our guide to reducing size safely. It may also be possible to pollard or coppice it, depending on the species.

For a full guide to pruning ornamental trees, see pruning established trees.

Pruning fruit trees

Fruit trees also need formative pruning in the first few years – see our guide to pruning new apples and pears and fan-trained trees: initial pruning.

Established fruit trees are best pruned once or twice a year, to keep them in good health and cropping well. Check out our selection of guides for full instructions:

• Apples and pears: pruning made easy
• Winter pruning apples and pears
• Summer pruning apples and pears
• Identifying fruit buds
• Pruning fan-trained trees
• Pruning plum trees

Fruit trees that are not pruned regularly will decline in health and productivity. To revive a neglected apple or pear tree, see our guide to renovating pruning.

Training

Fruit trees are often trained into formal shapes, such as fans and espaliers, against a wall or fence. This maximises the amount of fruit you can grow in a small space. Apple and pear trees can also be trained as step-overs – low-level horizontal edging for beds in a kitchen garden. See the following guides for more details:

• Espalier training
• Fan training
• Training step-over apple trees
• Training cordon apples

Another popular systems of formal training is pleaching, which is a way of interlacing the branches of a row of trees on a framework, to form a living screen. Lime trees and hornbeams are often used.

See our guide to pleaching.

Many trees can be raised from seed, although if the tree is a cultivar

Gardeners often use the word variety when referring to a specific plant, but the correct botanical term is 'cultivar'. Whichever word you use, it means a distinctive plant or plants, given a specific cultivar name and usually bred to enhance certain characteristics, such as flower or fruit size, colour, flavour or fragrance, plant size, hardiness, disease resistance, etc. Additionally, it is worth knowing that, botanically, variety has another meaning - it refers to a naturally-occurring distinct plant that only has slight differences in its looks. For example, Malva alcea var. fastigiata differs from typical plants by having an upright habit. , the offspring may differ slightly from the parent.

You can also take cuttings

A method of growing new plants from parts of an existing plant, such as sections of root, stem, leaf or bud. When prepared correctly and planted in the right conditions, they can produce roots and eventually become independent plants. There is a wide range of different methods for taking cuttings, depending on the plant and time of year. of most trees. There are three different types, taken at specific times of year:

• In spring and early summer, take softwood cuttings.
• In late summer to early autumn, take semi-ripe cuttings.
• In mid-autumn to late winter, take hardwood cuttings.

Experienced gardeners may also enjoy the challenge of propagating cultivars by grafting or budding (chip budding

Most established trees are robust, long-lived and relatively trouble-free, as long as they’re grown in conditions that suit their needs.

Signs of problems to look out for include:

• Brown leaves and Yellowing leaves can be caused by a number of problems.
• Bleeding from pruning cuts, especially those made in spring, may be problematic on several types of trees, including maples, walnuts and birches.
• General decline in health

Several pests and diseases can attack trees, including woolly aphids, honey fungus, silver leaf, bacterial canker, phythophthora root rot and verticillium wilt.

Newly planted trees are vulnerable and can suffer a range of setbacks – see our guide to establishment problems.

Unfortunately, trees can sometimes fail, and it’s worth finding out why, so you can prevent the same problem in other trees, and know whether you can replant – see our guide to common reasons trees and shrubs die. You could also consider getting in an expert arborist to inspect the dead tree.