Gardens have been a part of human civilization for at least 4,000 years. The earliest examples of horticulture date back to the 1500 BC, where lotus ponds surrounded by acacias and palms were depicted in Egyptian wall paintings. Since then, gardens have adapted new variations and uses, although the basic principles have always remained the same.

A garden serves as a means of displaying, cultivating and enjoying plants and other types of nature in a planned space, nowadays often featuring man-made materials such as garden sheds or log cabins. They can serve different purpouses to different people; some merely enjoy maintaining an appealing garden in which to spend their summer, some like to grow plants and vegetables in their greenhouse and some prefer to do both.

Whilst gardening is still an important part of our culture, there are certain threats that pose a substantial danger to the way we garden, in addition to the plants and animals that inhabit them.

Below is a rundown of five increasing threats to emerge into the world of gardening:

Rhododendron ponticum

A non-native plant to the UK, Rhododendron ponticum has caused a huge loss and abandonment of land throughout the British Isles. It was introduced to the UK in the late 18^th century.

Sometimes growing up to 8 metres in height, the plant effectively reduces the chances of survival for all surrounding plants, blocking the required light with its thick leaves. This in turn causes a loss to native wildlife who feed on such plants; particularly one of Britain’s most endangered species of mammal, the Dormouse.

In addition to this, Rhododendron acts as host to two plant diseases – phytophthora kernoviae and phytophthora ramorum. They are both fungal-like diseases which cause the death of plant species such as magnolia, kalmia and camellia. A National Trust adviser estimates that the diseases could have a severe impact on the environment and local economies, appearing in every garden in the UK 'within the next 20 years'.

Rhododendron is expensive to counteract and control, meaning land has been abandoned. Affected land can be restored, however, providing reinfestation is prevented.

Climate Change

An escalating issue in recent years, extreme temperatures and soil erosion are attributed to climate change. As plants and trees rely heavily on the weather and the subsequent sunlight and rainfall, a change in climate could most certainly have an effect on our gardens.

An examination of plant responses to the increase of temperature and carbon dioxide and changes in water supply revealed that plant life will face a number of challenges should the temperature continue to fluctuate.

The main cause for concern will be the increase in winter rainfall in contrast to drier summers. An excess in water can cause plants to drown, particularly in extreme cases such as flooding. On the other hand, a lack of water will result in plant life drying out and dying - especially in drought conditions.

Plant life in controlled environments such as botanic gardens stand much more a chance of withstanding climate change. Planted into carefully prepared ground, watered and sheltered as required and protected from pests, plants in propagation are far less at risk from climate change than in nature.

Chytridiomycosis

One of the joys of maintaining a garden is the wildlife it attracts, particularly those who inhabit the pond.

Sadly, there is a rapidly spreading disease called chytridiomycosis that is affecting amphibian populations the world over. Spread by a specific type of fungus (chytrid), the lethal disease spreads to such amphibians as frogs and salamanders through water or moist environments.

Chytridiomycosis kills by targeting the skin. Upon contracting the disease, the animal’s skin begins to thicken due to a change in the protein ‘keratin’. As frogs and salamanders often breathe and drink through their skin, this essentially suffocates the animal, causing an abnormal level of electrolyte levels.

Chytridiomycosis is a very high risk to the survival of certain amphibian species, with the International Union for Conservation of Nature calling it “the worst infectious disease ever recorded among vertebrates in terms of the number of species impacted, and its propensity to drive them to extinction.” With such diseases as this coupled with the loss of their habitat, it is important to do what we can in order to prevent such amphibiouscreatures from dying out.

Optimising one’s pond to accommodate for frogs is one way to counteract this substantial threat. For more information on how to help these garden inhabitants, read our article on frogs.

Citrus Longhorn Beetle

Another threat to UK gardens is the citrus longhorn beetle. Believed to have made its way into the UK on the backs of trees from the Far East, this non-native beetle is approximately one inch in length - white speckles on its back being its most identifiable feature.

Laying its larvae inside the trunks of shrubs and trees, gardens lay at risk due to the larvae feeding off and weakening the vascular system of plants and trees. It has already caused a lot of concern in the EU, prompting a ban on imports of Japanese maples from China.

In order to counteract the potential risk, FERA (Food and Environmental Research Agency) have asked anyone with a captured citrus longhorns to report to their local plant health and seeds inspector.

Moles

Whilst moles pose no serious long term threats to any plant species as such, they can certainly make a mess of a garden. Digging out a system of tunnels and chambers, these pests are attracted to soil and the earthworms/insects that inhabit it.

Although there are many mole traps available that can trap and/or kill the mole, it is far more effective and cheaper to detract them before they find their way into a garden. As they are claimed to dislike noise or disturbance, there are several devices that emit vibrations and buzzing, said to prevent moles from entering the vicinity when strategically placed.

In addition to this are the more homemade, experimental countermeasures. Some claim that placing garlic bulbs or pickled onions in the garden will deter moles, and some even put their faith in urine – cat, dog, even human!

Whatever the preference, however, it should be noted that the use of poison on moles is heavily regulated and may be illegal if the local council’s environmental department has not been contacted first.

Frogs

There are more than 5,000 recorded species of frog (order Anura) in the world, their habitats extending worldwide although they do not occur in the Antarctic nor are they present on many oceanic islands. They are tail-less amphibians; characterized by long hind legs, webbed feet, protruding eyes and a short body. They feed mostly on insects such as crickets, moths, flies and mosquitoes – although larger types of frog have been known to eat small turtles and even other small frogs.

They are capable of jumping incredible distances, with some recorded as leaping over 50 times their body length. This is due to their long hind legs and the way their tarsals, tibia and fibula have fused together to form a singular, strong bone. The bones in the frog’s forelimbs are also merged together in order to absorb the impact of each jump

The Frog Life Cycle

There are four main stages of the frog life cycle: egg, tadpole, metamorphosis and adult. It takes around 70 to 80 days for the frog to complete the egg to egg process.

When sexually active, the adult frogs will breed at a water source such as a stream or a pond. The males will make their signature mating call, a low croak, which will then attract nearby females. Once assembled, the male and female undergo their form of mating called ‘amplexus’, which results in a mass of upto 2000 gelatinous eggs that we call frogspawn. After about a week, these aquatic eggs will hatch and become tadpoles.

Tadpoles have oval bodies and long, flat tails. They are typically herbivores, feeding on algae within their native pond. However, there have been instances of some species being carnivorous at the tadpole stage, feeding on small insects and even other tadpoles. Those who develop legs early may be eaten by other tadpoles in order for them to survive longer.

After reaching the end of the tadpole stage, the frogs transition into adulthood through process of metamorphosis. They develop hind legs, front legs and then lungs. Their intestines change as their diet switches from herbivore to carnivore, followed by a change in their eyes in order to provide the frog with binocular vision. Finally, the frogs lose their tail and reach the adult stage.

Two tadpoles in the metamorphosis process

After reaching full maturity, the adult frogs will either leave the water for dry land, or continue to stay in their aquatic habitat. They will seek out invertebrates such as arthropods and gastropods, sometimes capturing prey with their hands and forcing it into their mouths, sometimes using their sticky tongues to catch fast-moving prey.

Frogs themselves are often preyed upon by birds, snakes, foxes, badgers and fish. Whilst it is not certain how long a frog can live for in the wild, they have been recorded to live for over 40 years in captivity.

Chytridiomycosis

There is a rapidly spreading disease called chytridiomycosis that is affecting amphibian populations the world over. Spread by a specific type of fungus (chytrid), the lethal disease spreads to such amphibians as frogs and salamanders through water or moist environments (seen as unusual as this particular form of fungus does not normally affect vertebrates).

“An extinction event on a scale equivalent to that of the dinosaurs”

Chytridiomycosis kills by targeting the skin. Upon contracting the disease, the animal’s skin begins to thicken due to a change in the protein ‘keratin’. As frogs and salamanders often breathe and drink through their skin, this essentially suffocates the animal, causing an abnormal level of electrolyte levels.

Chytridiomycosis is a very high risk to the survival of certain amphibian species, with the International Union for Conservation of Nature calling it “the worst infectious disease ever recorded among vertebrates in terms of the number of species impacted, and its propensity to drive them to extinction.” With such diseases as this coupled with the loss of their habitat, it is important to do what we can in order to prevent such amphibious creatures from dying out.

Frogs in the Garden

Due to these natural and manmade threats, allowing frogs to live in our garden not only brings in a touch of wildlife, but can also help prevent their numbers from diminishing. They need moisture, food, shelter and a place to mate, so making a few changes will make it possible for almost any garden to become a safe frog haven.

Pond

A pond should be around 2-3 feet in depth in order for it to be accommodating for frogs. The edges should be shallow in order for them to get in and out with ease, and there should be moist, rough vegetation in close proximity where the frogs can find food and hibernation. It will also be necessary to provide shelter from the summer sun, meaning pond plants such as marigolds and violets will be a welcoming addition. Damp soil around the pond is often required as their skin needs to stay moist in order for them to breathe. Frogs also tend to prefer ponds with no fish.

Food

As highlighted earlier, frogs tend to live on a diet of mainly insects; the same insects who are a nuisance to homeowners and their gardens. Mosquitoes, moths, slugs, snails, flies and even cockroaches can be reduced in numbers by having frogs in the garden and thus potentially saving the job of calling in pest control should the garden/home become infested with insects. Not only does this save money, but it removes the need to use chemicals that could potentially harm grass, plants and flowers.

Surrounding area

Although it is necessary to have a pond in the garden to attract frogs, it is actually the surrounding area in which they will spend the majority of their lives - so forming piles of leaves, rocks and other debris will provide a place for frogs to forage and shelter in. Using toxic substances in the garden is not advisable due to the way in which frogs breathe through their skin – such pesticides as slug pellets are no longer necessary anyway due to the fact that slugs are eaten by frogs. In keeping with their desire for the damp, they will often choose to spend their time in the moist, humid atmosphere of the greenhouse.

Maintenance

Although having frogs in the garden can be a pleasure and many will strive to maintain a comfortable environment for them, there are a few things to avoid in order to keep them safe and healthy.

For example, grass should be kept short at all times, as frogs will sometimes shelter in long grass which puts them at risk when mowing or strimming is required. Keeping it a short length will make it easier to spot any foraging frogs before they meet a rather grisly end.

It is not a wise idea to remove a frog its original habitat and place it in a different one, as it will most likely die or migrate. If a garden offers their basic needs then frogs will arrive naturally over time – trying to force them into a new environment will not work.

Finally, if a frog is spotted motionless at the bottom of a pond during winter, then do not attempt to retrieve it. Frogs hibernate during the winter, and some males will bury themselves in mud and lie dormant at the bottom of the pond. Removing the frog will disturb its hibernation process and potentially kill it.

Having frogs in the garden does not require too much maintenance but they are relatively fragile creatures so by following the advice here, the perfect garden environment can be created in which they can prosper.