Plants can survive frosts by several mechanisms:

1. Sometimes bark can insulate the living water-conductive tissues in the same way that water pipes are lagged to prevent water freezing within cells

2. Some plants accumulate materials, certain sugars and amino acids for example, that act as anti-freeze lowering the freezing point of cell contents – shortening autumn days induce this

3. A more effective mechanism is the ability of some plants to allow their cell contents to ‘superfreeze’ where the cell contents remain liquid even though below freezing point. To do this plants have to experience several days of cold weather before the freeze and this explains why even hardy plants can be damaged by a sudden autumn frost

4. In very severe climates such as within the arctic circle

   A native plant is one that originated or arrived naturally in a particular place without human involvement. In the British Isles, native plants are those that were here during the last ice age or have arrived unaided since.

   native trees remove water from their cells, tolerating the dehydration of the cell contents, and place the water between the cells where it can freeze without causing damage. This works where the weather provides a prolonged slow chilling

Sometimes frost damage is apparent almost immediately following freezing. However, this is not always the case and with some plants, particularly woody ones, the damage may take several months to appear. Look out for the following signs:

• Tender young growth may be damaged by spring frosts, causing scorching and pale brown patches to appear between the leaf veins. This tends to be on the exposed and top edges of the plant e.g. acer and carpenteria
• Hard frost in winter can cause the leaves of hardy evergreen plants to be scorched and turn brown, and may eventually lead to the death of the plant, e.g. bay and pittosporum
• The foliage of tender
  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 e.g. dahlia and canna may be blackened by the first frost of autumn. Stems usually collapse
• Spring frosts can damage blossom and young fruits. This may cause a corky layer to form at the flower end of the fruit i.e. apple and damage to blossom may lead to few or no fruits forming
• As a result of late spring frosts 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 and tender vegetables, such as potatoes and tomatoes, may suffer from leaf scorch, browning and even total plant death
• Prolonged periods of frost may cause spotting on the leaves of some shrubs such as photinia and garrya
• The foliage of certain plants exhibiting early symptoms of frost damage appears water-soaked and dark-green, turning black in time

Ground frost occurs when the temperature of the ground falls below freezing point (0ºC/32ºF) and air frost occurs when the temperature of the air falls below freezing point.

Plant cells can be damaged or even destroyed by frost. Repeated freezing and thawing, or very rapid thawing can be particularly damaging to plants.

Once the temperature has fallen below freezing, a strong wind can make a frost more damaging. Cold winds remove moisture from evergreen foliage more quickly than it can be replenished by the roots; this can cause leaf browning particularly at the tips and margins.

Tender plants survive the winter better when they are planted in a sheltered sunny position. This is because new wood is ripened by the sun accumulating more carbohydrates during the growing season, making it more frost resistant.

Newly planted, young plants can be more susceptible to frost damage than fully established specimens.
Cold air naturally flows downwards on sloping ground, collecting at the lowest point or against a barrier, this is known as a frost pocket.

There are a number of ways to keep your plants safe during cold weather:

• Choose plants that are reliably hardy and suited to your growing conditions. The RHS Plant Selector can help you choose hardy plants

• Select planting positions carefully to avoid frost pockets

• Slightly tender plants should be grown in a warm sunny spot, e.g. against a south-facing wall, which will provide some extra warmth and winter protection

• Cover plants with a double layer of biodegradable or re-used old fleece, or other suitable protection such as an old sheet, overnight when frost is forecast

• Mulch the root area of evergreens, conifers, tender shrubs and tender

  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 with a thick layer of organic matter to prevent the ground becoming frozen

• Move container-grown plants to a sheltered part of the garden in cold weather and provide some extra protection by wrapping the pot in bubble wrap

• Ensure tender plants are overwintered safely in the greenhouse by providing adequate heating or insulation

• Leave the previous seasons’ growth on more tender plants until spring, for example penstemon, as this provides valuable frost protection during the winter

• Tender plants can be lifted or moved to a more sheltered position or greenhouse. If this isn’t practical, then protect them by wrapping – examples include bananas and tree ferns. Lift tender perennials such as dahlias, cannas, pelargoniums and fuchsias before the first frosts

• Protect fruit and strawberries from frost by packing with bracken or straw

• Avoid applying nitrogen-rich fertilisers late in the season as they stimulate soft, sappy growth, which is especially vulnerable to frost damage

• Plants exposed to early morning sun may thaw too rapidly after a frost, causing damage to flowers and young growth. Camellia and magnolia flowers in particular can be ruined by a single frost

• Plant tender bedding plants out after the danger of frost has passed – this is generally early May in London and the south west, mid-May in the south of England, late May for much of England and Wales, and June in Scotland and hilly areas of northern England and Wales. Always harden off plants before planting outside

• If no more frost is expected, prune out damaged growth, cutting to an undamaged sideshoot or bud

• After pruning, apply a top dressing of a general-purpose fertiliser, such as Growmore, at the manufacturer’s recommended rate, to encourage strong re-growth

• If a fence or hedge is causing a ‘frost pocket’ consider creating a gap, or remove some of the lower growth to improve cold air drainage

• Frost may lift newly planted shrubs out of the ground, so check and re-firm the soil around them

• In gardens exposed to cold winds, consider creating more protection by planting a shelterbelt

• Even though the foliage of plants such as dahlias and cannas has been blackened by frost, the roots are alive and can still be protected or lifted and stored

Important: Don’t just give up on a plant that has been frost damaged. Many plants can be surprisingly resilient and may well rejuvenate from

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.

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

Though brown leaves may make a plant look dead, don’t give up on it before summer – it may re-shoot from lower down