Growth occurs when cells divide, differentiate (become specialised to a particular function) and elongate. In plants, this occurs in growing zones called

Meristem is a type of tissue that is responsible for growth and development in plants. It consists of unspecialised cells that can divide and diversify into various types of specialised cells. Meristems are only found in certain parts of a plant, such as at root and shoot tips and in bundles between xylem and phloem vessels.

Gibberellins are a group of plant hormones that play a role in regulating plant growth and development, particularly in stem elongation, seed germination and flowering. They are also involved in the production of chlorophyll and the regulation of fruit development.

gibberellin

The meristems found inside stems and roots are responsible for making a plant wider and thicker, which ensures it can support the weight of its leaves, flowers and fruit.

In most plants, growth happens at the terminal (apical)

A bud is a small, undeveloped shoot that contains the potential for new growth. Buds are typically found on stems, where they can be apical (found at the tip) or axillary (found between leaf axils) and may develop into leaves, shoots or flowers.

Auxin is a plant hormone that plays a role in regulating plant growth and development, particularly in cell elongation, root formation and apical dominance (where the main stem is dominant over other side stems). It is also involved in many other processes, including phototropism (the bending of plants towards light), gravitropism (the response of plants to gravity) and the development of fruit and flowers.

auxins

A bud is a small, undeveloped shoot that contains the potential for new growth. Buds are typically found on stems, where they can be apical (found at the tip) or axillary (found between leaf axils) and may develop into leaves, shoots or flowers.

buds

Meristem is a type of tissue that is responsible for growth and development in plants. It consists of unspecialised cells that can divide and diversify into various types of specialised cells. Meristems are only found in certain parts of a plant, such as at root and shoot tips and in bundles between xylem and phloem vessels.

meristematic tissue

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An apical bud controls the growth of axillary buds lower on the stem

Grasses and grass-like plants have their active growing zone (meristem) at their base rather than the tip. This means that when you mow your lawn, cutting off the leaf tips, the grass can continue to grow.

As plants grow, their stems get thicker and sturdier to provide support. Soft green shoots gradually become woody and less flexible and tree trunks increase in girth. 

This thickening is produced by a meristem, called cambium tissue, found inside stems. Its dividing cells produce more (secondary)

Xylem vessels are the pipework in plant stems that transport water and minerals from the roots to the rest of the plant.

Part of a plant's vascular system (internal plumbing) responsible for transporting sugars and other products of photosynthesis from leaves to the rest of the plant.

phloem

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A cross-section through a stem

In green stems, cambium is spread through the tissue in bundles sandwiched between the xylem and phloem. In woody stems, over time, these join to become rings of tissue. This is sapwood, a soft outer layer lying between the inner heartwood and the bark.

Xylem vessels made in spring carry more water up from the roots than those made in summer and autumn, so spring sapwood is lighter in colour. A distinct line forms each year where the two tissues meet, and by counting the 'tree rings', it’s possible to estimate the age of a tree.   

Annual growth rings at the base of a side branch

Trunk girth is also a useful indication of age. If you buy a young tree from a nursery, you’ll often find that the circumference of the trunk at 1m (3¼ft) in height is provided, to indicate the tree’s maturity and define its price. 

The price of these rootballed trees will be determined by trunk girth

Bark, the protective outer layer on woody stems (and roots), is produced by another meristem, the cork cambium.

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.

Roots grow into the soil searching for

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 plant nutrients usually derived from soil are nitrogen, phosphorus and potassium, while carbon, oxygen and hydrogen are absorbed from the air. Other vital soil nutrients include magnesium, calcium and sulphur. Most garden soils contain enough nutrients to promote healthy plant growth.

The root system of Festuca glauca

There are two types of roots:  

Tap roots naturally grow straight downwards to seek out water and nutrients deep in the soil. They provide good anchorage and are often thickened with stored starch. In many trees, the tap root fades away over time as other roots develop.

As tap-rooted plants don’t transplant well, are hard to grow in containers and have fewer fine roots for water absorption, many tree nurseries undercut young trees, severing their tap root, to encourage more fibrous root growth. This makes them easier to manage and reduces transplant shock.  

Fibrous roots form a fine, branching network with a large surface area for absorption. They are found just below the soil surface and collect water and nutrients percolating through the soil. 

Around 90% of tree roots are found in the top 60cm (2ft) of soil, and as fibrous roots are easily damaged, it’s important not to compact this rootzone area, for example by parking cars under a tree’s canopy. 

Plants with taproots, such as carrots, don't usually transplant well

Fibrous roots branch outwards into the upper layers of soil

Roots initiate branching internally, from an area around their central core where their

A plant‘s vascular system is like its internal plumbing – a network of ‘pipes’ that transport important materials. The vascular system in plants consists of two types of tissue: xylem and phloem. Xylem is responsible for transporting water and minerals upwards from the roots to the rest of the plant, while phloem transports sugars and other organic compounds produced by photosynthesis from the leaves to the rest of the plant.

A bud is a small, undeveloped shoot that contains the potential for new growth. Buds are typically found on stems, where they can be apical (found at the tip) or axillary (found between leaf axils) and may develop into leaves, shoots or flowers.

buds

Now you know more about how plants grow, put this into practice to help your plants thrive:

• Pinch out the tips of summer
  Bedding plants are usually colourful half-hardy, short-lived or annual plants, grown for displays in beds or containers. They may be changed seasonally, with spring, summer and winter bedding displays each using different plants of appropriate hardiness and flowering times.

  bedding plants to improve their flowering display. Also see our guide to bedding plants
• Trim hedges regularly to increase their density. Most hedges benefit from trimming once or twice during the
  The period of time when an individual plant is in active growth. This will depend on the local climate and light levels, and can vary between different plants, although it is broadly from spring to autumn.

  growing season
• Consider trunk diameter and look for a balanced ratio of roots to shoots when you next buy a tree – the thickness of the trunk gives you an idea of its age, which is useful when comparing prices, and a well-balanced tree should establish better. See our guide to buying trees
• Avoid moving plants with a taproot, as they have fewer fine feeder roots and often don't recover well if disturbed. This includes edibles like carrots, parsnips and dill, which are best sown in situ, and
  Perennials are plants that live for multiple years. They come in all shapes and sizes and fill our gardens with colourful flowers and ornamental foliage. Many are hardy and can survive outdoors all year round, while less hardy types need protection over winter. The term herbaceous perennial is used to describe long-lived plants without a permanent woody structure (they die back to ground level each autumn), distinguishing them from trees, shrubs and sub-shrubs.

  perennials like sea holly (Eryngium) and oriental poppies (Papaver orientale)  
• Loosen the soil at the edges of a planting hole to make it easier for roots to grow and branch. See our step-by-step guide to planting a tree