top of page
Green Fingers

Ponds are essential


Week 38


I have just returned from foraging and have gathered a large number of blackberries. There is something attractive about eating my own fruits, but I suspect the seasons are against me. I have likely collected my final harvest before the remainder of my softening blackberries are guzzled by the birds and autumn takes over. Birds love blackberries, I love blackberries, as do caterpillars, butterflies, dormice, squirrels, deer, foxes, cows, bats, and badgers[i],[ii]. There is fierce competition for them, so I am glad to have had my fill. Blackberries are the fruit of a bramble, so it puzzles me why so many people hate brambles and pull them out on sight. Personally, I do not see brambles as troublesome and take time to weave them this way and that through my hedging.

Blackberries
My very own blackberries

Blackberries have been eaten for many centuries. One of the earliest known examples of their consumption was from the remains of the Haraldskær Woman, the naturally preserved bog body of a Danish woman dating from, probably, the 5th century BC[iii]. Forensic evidence found blackberries in her stomach contents, as well as other foods. In the London Pharmacopoeia of 1696, the use of blackberries to make wines and cordials was also documented and there is a long culinary history of blackberry use alongside other fruits to make pies, jellies, and jams. Blackberry plants were used for traditional medicine by the Greeks, as well as aboriginal Americans. A 1771 document[iv] described brewing blackberry leaves, stem, and bark for stomach ulcers, while the fruit, leaves, and stems have been used to dye fabrics and hair. Native Americans were even known to use the stems to make rope. The shrubs have also been used for barriers around buildings, crops, and livestock[v].


As with so many popular plants, blackberries also come with a copious folklore. For example, it is said they should not be picked after Old Michaelmas Day (11 October) as the Devil will have made them unfit to eat by stepping, spitting, or fouling on them. Meanwhile Jesus’ crown of thorns was also said to have been made of brambles, which gives them a special place.

Silver birch seedlings
Lots of silver birch on what was once Stripy Lawn

I can happily report, although realise this may be premature, that the oak powdery mildew I recently saw on some of my oak saplings is receding. I must hope it is the diluted milk treatment I have been using. The regime is to repeat the treatment every 14 days, so I will spray more milk, until the oak leaves turn brown and fall. Meanwhile I must start thinking about which saplings to move and which should remain where they are. It is evident that, given its own head, my land wishes to be woodland. Where there was once stripy lawn, there is now scythed grass, but there are tree seedlings and saplings almost wherever I look. There is alder[vi], broad-leaved lime[vii], sycamore[viii], Norway maple[ix], silver birch[x], rowan[xi], willow[xii], beech[xiii], yew[xiv], larch[xv], chestnut[xvi], oak[xvii] and so many more. All are springing up where once a lawn mower would have beheaded them. It escapes me why the regular cutting of grass is seen by so many as still being acceptable.

Willow seedling
A willow seedling - do I move you or let you stay where you are?

As climate change progresses, I am pleased to see these emerging trees, as they are growing between my house and the sun and will automatically provide shade and cooling. The strategic planting of trees in urban areas can cool the air by up to 8°C, which is essential for cities as they are presently warming 29% faster than rural areas[xviii]. Consequently, I am not about to lose my trees, even if I live in the countryside. Yet it does mean that slowly my land will convert to woodland and my grassland will shrink. These are changes ahead that I must encourage.


I have workmen at my house for the next few weeks - they are sorting out my roof - and I am miles from the nearest public toilet. The men frequently ask where they should take a pee. My answer is simple - they should pee on my boundary, immediately beside the wire fence that the badgers have gnawed through en route to digging up my land. If a wire fence must be used to deter badgers, the wire needs to be extra-strong. Mine clearly is not. Badgers do what is known as musking[xix], which means marking their presence by giving off scent. This is normally sweat, urine or faeces. Badgers also have a subcaudal gland near the base of the tail, which is used when the animals musk each other. Yet anything a badger can do, a human can try, so peeing on a boundary is one way of deterring badgers. The workmen have been delighted to assist, although this human musking must be frequently repeated, perhaps every 10 days. Theoretically, this technique must be used all year, as badgers do not hibernate, although they do reduce their nocturnal activities as the weather becomes colder. Their main activity is seen during their mating season, which is late winter to early spring[xx].

Shade from trees is critical (Image by Karsten Paulick from Pixabay)
Shade from trees is critical (Image by Karsten Paulick from Pixabay)

I am not sure what it is about a pond, but I have a small one on my land that is frequently a focal point for anyone who chooses to visit. A pond is perfect not only for peace, quiet and relaxation, but it is also a biodiversity hotspot[xxi]. Thanks to the reflective properties of water, the pond also helps improve the lighting in its area.


My pond has been present for many years, which is why I am lucky, but when making changes to it, or even making a new one, autumn and winter are ideal times. A pond does not work in isolation, so it is good to leave the vegetation long around part of it, which gives perfect cover for wildlife exiting or entering the pond. One edge should also be kept open, especially if the sun strikes it on occasion, as it is in this open area that one is likely to find animals basking[xxii].

Goldfish in pond
Fish can cause trouble in ponds

Fish are bad news for a pond - I have none - as they eat many of the insects one is trying to encourage. Fish are voracious predators and can raise nutrient levels, which encourages algae[xxiii], including blanket weed[xxiv]. Blanket weed is a common type of alga that can be found in garden ponds, mainly in spring and summer. It comprises masses of tangled green strands that if allowed to escape control, can inhibit the growth of other plants[xxv].


Numerous studies have demonstrated the positive impact of ponds on biodiversity. One excellent piece of work from Southern England in 2004[xxvi] showed that although all waterbody types contributed to the diversity of macrophytes and macroinvertebrates in a region, they differed in relative value. Ponds contributed most to biodiversity, supporting considerably more species than other types of waterbody. Streams typically supported fewer species than either ponds or rivers. Ditches, most of which were seasonal, were the least species-rich habitat. Ponds are a no-brainer. If you do not have one, but have space, please make one right away. It will work wonders for biodiversity, in a way that few other things can achieve.

Blanket weed
Blanket weed (courtesy Martinotero)

In addition to biodiversity, ponds are also good for conserving water. They act as a reservoir for rainwater and help maintain soil moisture levels during dry periods. This can be especially beneficial in regions with periodic droughts, where gardens can struggle to retain water. A well-designed pond can be an integral part of a sustainable garden, as it is for mine. Ponds can also help filter and purify rainwater, preventing runoff of pollutants into nearby streams and rivers[xxvii].


Then there is carbon sequestration, at which ponds are fantastic, and which is essential for helping mitigate climate change. The submerged plants and organic matter that accumulate in ponds can store carbon over time and help reduce the amount of carbon dioxide in the atmosphere. One piece of research from California in 2015[xxviii] suggested that the world's farm ponds alone may bury more organic carbon than the oceans, and 33% as much as the world's rivers deliver to the sea.


There are also the educational and aesthetic[xxix] opportunities offered by a pond, as plenty of those who visit my land stop at my pond to see what is happening. Both children and adults can see the interactions between aquatic plants, insects, amphibians, and other wildlife. This leads to a greater appreciation for the natural world and a deeper understanding of ecosystems. It is one very good reason why I am happy for schools and community organisations to use my renatured land as an outdoor classroom[xxx].

Dragonfly (James Wainscoat on Unsplash)
Dragonfly (James Wainscoat on Unsplash)

Insects adore ponds. Lessons from farmlands, where there has been extensive infilling of ponds for many decades, have shown that ponds need to be managed, because if they are, then the abundance of insects is much greater. With an increase in insects comes an increase in birdlife, which in recent times have shown a severe decline in numbers[xxxi]. It is essential to look after a pond. In the last 100 years, roughly 90% of the natural wetland habitat in the UK has been lost, as has 50% of the insect biomass[xxxii]. These are huge numbers, which cannot be ignored. Yet in my pond over time, I have seen dragonflies[xxxiii], damselflies[xxxiv], mayflies[xxxv], hoverflies[xxxvi],[xxxvii], and gnats[xxxviii], as well as underwater insects like diving beetles[xxxix], lesser water boatmen[xl], whirligig beetles[xli], water scorpions[xlii], and water stick insects[xliii]. All of these are food for birds, bats, and other insects.

Garden pond with flag iris
My tiny pond, with plenty of cover around it and invasive flag iris that needs trimming

Sadly, ponds are not all good news. Mine leaks, so I must refill it from time to time, and it is not especially cheap to maintain. Keeping it healthy and aesthetically pleasing requires regular cleaning, removal of excess vegetation, and occasional repairs. Ponds can also become a breeding ground for invasive species, both in terms of aquatic plants and animals. Non-native species can outcompete native ones and disrupt the balance of the ecosystem. Regular monitoring and management are necessary to prevent or control invasive species in and around the pond. If I neglect to maintain my pond then its water quality can fall, which leads to algal blooms or excessive nutrient build-up. These then harm the ecosystem I am attempting to conserve.


Another problem with my pond is that it is unfenced, which can pose a safety risk, especially for young children, or any pets. Accidental drowning is a serious concern, and I cannot forget that a young child can drown in as little as 5cms of water[xliv]. As for animals, in the USA alone, 40,000 pets drown each year[xlv].


Ponds may be wonderful places, but they can also be a danger.


***



Acknowledgement

Take it from me - none of this would be possible without the help of RSG Horticulture. Rufus, who runs it, has far more energy than me and is full of ideas and skills. Do contact him through https://www.rsghorticulture.com.


Hashtags


References [i] Torrance J. Nature’s feast of early autumn fruits. 8 September 2010. See https://www.bbc.co.uk/blogs/natureuk/2010/09/early-autumn-fruits.shtml#:~:text=Many%20caterpillars%20live%20on%20blackberry,and%20badgers%20love%20blackberries%20too!. Accessed 15 September 2023. [ii] Louise. 13 animals that eat blackberries (pictures, facts). See https://wildlifeinformer.com/animals-that-eat-blackberries/. Accessed 15 September 2023. [iii] Archaeological Institute Haraldskaer Woman: Bodies of the Bogs, Archaeology, Archaeological Institute of America, December 10, 1997. [iv] Harding D. The History of the Blackberry Fruit. gardenguides.com. Garden Guides, Leaf Group Ltd. Retrieved 20 June 2019. [v] Wikipedia. Blackberry. See https://en.wikipedia.org/wiki/Blackberry. Accessed 15 September 2023. [vi] See week 24 entry. [vii] Wikipedia. Tilia. The tree is known as linden for the European species. The linden is recommended as an ornamental tree when a mass of foliage or a deep shade is desired. It produces fragrant and nectar-producing flowers and is an important honey plant for beekeepers, giving rise to a pale but richly flavoured monofloral honey. In European and North American herbal medicine, the flowers are also used for herbal teas and tinctures. The flowers are used for herbal tea in the winter in Greece and Turkey. In China, dried Tiliaflowers are also used to make tea. In English landscape gardens, avenues of linden trees were fashionable, especially during the late 17th and early 18th centuries. Many country houses have a surviving "lime avenue" or "lime walk", the example at Hatfield House was planted between 1700 and 1730. The fashion was derived from the earlier practice of planting lindens in lines as shade trees in Germany, the Netherlands, Belgium and northern France. Most of the trees used in British gardens were cultivars propagated by layering in the Netherlands. See https://en.wikipedia.org/wiki/Tilia. Accessed 17 September 2023. [viii] See weeks 6, 23, and 34 entries. [ix] See week 23 entry. [x] See weeks 6, 31, and 34 entries. [xi] See weeks 4 and 34 entries. [xii] See week 23 entry. [xiii] See weeks 23, 34, and 37 entries. [xiv] See weeks, 2, 4, 23, and 31 entries. [xv] See week 23 entry. [xvi] See weeks 23 and 34 entries. [xvii] See weeks 1, 31, 34, and 37 entries. [xviii] How trees keep things cool. 13 July 2022. https://www.treesforcities.org/stories/how-trees-keep-things-cool#:~:text=They%20absorb%20water%20and%20then,cooling%20and%20less%20energy%20usage. Accessed 16 September 2023. [xix] Badgers – scent marking. See http://www.newforestexplorersguide.co.uk/wildlife/mammals/badgers/scent-marking.html. Accessed 16 September 2023. [xx] Department of Agriculture, Environment and Rural Affairs. Advice on badgers. See https://www.daera-ni.gov.uk/articles/advice-badgers#:~:text=Badgers%20are%20largely%20nocturnal.,in%20late%20winter%2Fearly%20spring. Accessed 16 September 2023. [xxi] Dalesway. Top benefits of having a garden pond. See https://daleswaypaving.com/top-benefits-of-having-a-garden-pond/#:~:text=When%20you%20add%20a%20garden,all%20pervasive%20in%20rural%20areas. Accessed 14 September 2023. [xxii] RHS. Wildlife ponds. See https://www.rhs.org.uk/ponds/wildlife-ponds. Accessed 14 September 2023. [xxiii] Lewin RA, Andersen RA. "algae". Encyclopedia Britannica, 26 Apr. 2023, See https://www.britannica.com/science/algae. Accessed 14 September 2023. [xxiv] Wikipedia. Spirogyra. Spirogyra (common names include water silk, mermaid's tresses, and blanket weed) is a genus of filamentous charophyte green algae of the order Zygnematales, named for the helical or spiral arrangement of the chloroplasts that is characteristic of the genus. Spirogyra species, of which there are more than 400, are commonly found in freshwater habitats. Spirogyrameasures approximately 10 to 100 μm in width and may grow to several centimetres in length. It is often observed as green slimy patches on the ground near ponds and other water bodies having stagnant water. See https://en.wikipedia.org/wiki/Spirogyra. Accessed 14 September 2023. [xxv] Fisher S. How to get rid of blanket weed. I May 2023. See https://www.gardenersworld.com/how-to/solve-problems/blanket-weed-treatments/. Accessed 14 September 2023. [xxvi] Williams P, Whitfield M, Biggs J, Bray S, Fox G, Nicolet P, Sear D. Comparative biodiversity of rivers, streams, ditches and ponds in an agricultural landscape in Southern England. Biological conservation. 2004 Feb 1;115(2):329-41. [xxvii] Birk S, Chapman DS, Carvalho L, Spears BM, Andersen HE, Argillier C, et al. Impacts of multiple stressors on freshwater biota across spatial scales and ecosystems. Nature Ecology & Evolution, 2015;1(9), 114. [xxviii] Downing JA, Cole, JJ, Middelburg JJ, Striegl RG, Duarte CM, Kortelainen P, Prairie YT, Laube KA. Sediment organic carbon burial in agriculturally eutrophic impoundments over the last century, Global Biogeochem. Cycles, 2008;22, GB1018, doi:10.1029/2006GB002854. [xxix] Gledhill DG, James P, Davies DH. Urban pond: a landscape of multiple meanings. In 5th international postgraduate research conference in the built and human environment. University of Salford, UK 2005. [xxx] Bates C. Rewilding education? Exploring an imagined and experienced outdoor learning space, Children's Geographies 2020;18:3, 364-374, DOI: 10.1080/14733285.2019.1673880 [xxxi] Lewis-Phillips J, Brooks SJ, Sayer CD, Patmore IR, Hilton GM, Harrison A, Robson H, Axmacher JC. Ponds as insect chimneys: Restoring overgrown farmland ponds benefits birds through elevated productivity of emerging aquatic insects, Biological Conservation 2020;241, 108253 [xxxii] Price C. Garden ponds for insects. See https://www.shropshirewildlifetrust.org.uk/blog/dr-cath-price/garden-ponds-insects#:~:text=Hoverflies%20produce%20the%20unattractively%2Dnamed,birds%2C%20bats%20and%20other%20insects. Accessed 14 September 2023. [xxxiii] See week 27 entry. [xxxiv] Wikipedia. Damselfly. Damselflies are flying insects of the suborder Zygoptera in the order Odonata. They are similar to dragonflies (which constitute the other odonatan suborder, Anisoptera) but are smaller and have slimmer bodies. Most species fold the wings along the body when at rest, unlike dragonflies which hold the wings flat and away from the body. An ancient group, damselflies have existed since at least the Lower Permian beginning about 299 million years ago and are found on every continent except Antarctica. All damselflies are predatory insects; both nymphs and adults actively hunt and eat other insects. The nymphs are aquatic, with different species living in a variety of freshwater habitats including acidic bogs, ponds, lakes, and rivers. Their presence on a body of water indicates that it is relatively unpolluted, but their dependence on freshwater makes them vulnerable to damage to their wetland habitats. Artificial fishing flies that mimic damselfly nymphs are used in wet-fly fishing. Damselflies are sometimes represented in personal jewellery such as brooches. See https://en.wikipedia.org/wiki/Damselfly. Accessed 14 September 2023. [xxxv] Common mayfly (Ephemera danica). The common, or 'green drake', mayfly is one of 51 species of mayfly in the UK, and is on the wing from April until September (nymphs are present all year-round). Mayflies are common around freshwater wetlands, from fast-flowing rivers to still lakes, where the larvae spend their lives underwater, feeding on algae and plants. In the summer, the adults hatch out - sometimes simultaneously and in their hundreds; they have very short lives (just hours in some cases), during which they display and breed. Many species do not feed as adults as their sole purpose is to reproduce, dying once they have mated. The name 'mayfly' is misleading as many mayflies can be seen all year-round, although one species does emerge in sync with the blooming of hawthorn (or 'mayflower'). See https://www.shropshirewildlifetrust.org.uk/wildlife-explorer/invertebrates/other-insects/common-mayfly. Accessed 14 September 2023. [xxxvi] Common banded hoverfly (Syrphus ribesli). The Common banded hoverfly is a very common hoverfly found along hedgerows, and in gardens and woodlands. Adults feed on the nectar of flowers, while the larvae are predators of aphids. This hoverfly has multiple broods; adults are seen throughout spring and summer, while the larvae survive the winter as pupae. The Common banded hoverfly creates a hum when resting by vibrating its wings. See https://www.shropshirewildlifetrust.org.uk/wildlife-explorer/invertebrates/flies/common-banded-hoverfly. Accessed 14 September 2023. [xxxvii] See week 27 entry. [xxxviii] Wikipedia. Gnat. A gnat is any of many species of tiny flying insects in the dipterid suborder Nematocera and can be both biting and non-biting. Most often they fly in large numbers, called clouds. "Gnat" is a loose descriptive category rather than a phylogenetic or other technical term, so there is no scientific consensus on what constitutes a gnat. Some entomologists consider only non-biting flies to be gnats. See https://en.wikipedia.org/wiki/Gnat. Accessed 14 September 2023. [xxxix] Great diving beetle (Dytiscus marginalis). The great diving beetle is a large and voracious predator of ponds and slow-moving waterways. Blackish-green in colour, it can be spotted coming to the surface to replenish the air supply it stores beneath its wing cases. See https://www.wildlifetrusts.org/wildlife-explorer/invertebrates/beetles/great-diving-beetle#:~:text=The%20Great%20diving%20beetle%20is%20a%20very%20large%20diving%20beetle,tadpoles%20and%20even%20small%20fish. Accessed 14 September 2023. [xl] Lesser water boatmen (Corixa punctata). This brown bug lives in water. It has long hind legs, covered in hairs, that it uses rather like paddles to swim. Its middle legs are slightly shorter, but its front legs are very short and are used to scoop up food. Water boatmen are common and widespread throughout Britain – you’ll find them in most weedy ponds, lakes and slow-flowing rivers. They spend most of their time at the bottom, coming to the surface only to renew their air supply. Males attract females with a ‘courtship song’, produce by rubbing their front legs against a ridge on their head. Females lay single eggs, which they attach to plant stems or floating algae. See https://www.rspb.org.uk/birds-and-wildlife/wildlife-guides/other-garden-wildlife/insects-and-other-invertebrates/beetles-and-bugs/water-boatman/. Accessed 14 September 2023. [xli] Wikipedia. Whirligig beetle. The whirligig beetles are water beetles, comprising the family Gyrinidae that usually swim on the surface of the water if undisturbed, though they swim underwater when threatened. They get their common name from their habit of swimming rapidly in circles when alarmed and are also notable for their divided eyes which are believed to enable them to see both above and below water. Whirligig beetles are most conspicuous for their bewildering swimming. They can be difficult to see if they are not moving or are under water. See https://en.wikipedia.org/wiki/Whirligig_beetle. Accessed 14 September 2023. [xlii] Water scorpion (Nepa cinerea). The water scorpion is not a true scorpion, but it is certainly an underwater predator, and uses its front pincer-like legs to catch its prey. Its tail acts as a snorkel, rather than a sting, so it can breathe in the water. See https://www.wildlifetrusts.org/wildlife-explorer/invertebrates/bugs/water-scorpion. Accessed 14 September 2023. [xliii] Water stick insect (Ranatra linearis). The Water Stick Insect is the largest water insect in Europe and looks like a mantis. It has a 4 cm body length (7 cm including the breathing tube). It relies on camouflage for protection, when threatened it will adopt a stiff and dead posture to mimic a little stick; and with its legs pressed against the body you could easily take it for a piece of old reed. Its tail acts as a snorkel, so it can breathe in the water. See https://www.naturespot.org.uk/species/water-stick-insect. Accessed 14 September 2023. [xliv] Drowning. See https://www.rospa.com/resources/hubs/keeping-kids-safe/drowning#:~:text=Ponds%20make%20a%20great%20garden,Our%20advice%20is%20simple. Accessed 14 September 2023. [xlv] CityVet. Keeping your dog safe in and around water. See https://www.cityvet.com/dog-water-safety/#:~:text=Remember%2C%20each%20year%20around%2040%2C000,many%20may%20fear%20the%20water. Accessed 16 September 2023.

Comments


bottom of page