I often get asked which species of turtles can be kept in a garden pond. The first thing to remember is that there are no naturally occurring species of turtle in the UK (Unless we count Britain’s Lost Turtle – emys orbicularis the European Pond Turtle…) where they are found in most other places in the world. This is mainly due to climatic suitability, in North America there are long hot summers with deep cold winters and a very short and rapidly changing spring and autumn. In South America and Africa it can be hot all year round. In the UK we have a cool temperate summer, a mild wet winter and long, drawn-out, springs and autumns. We need to choose our turtle species carefully to ensure survival. We will first discuss species that can remain outdoors all year round.
The first, most obvious, choice is emys orbicularis orbicularis – the European Pond Turtle. This species occurred naturally in the UK 5,000 to 10,000 years ago and is found across Europe in similar altitudes. There is currently a movement amongst Rewilders to reintroduce this species to the UK and have it reclassified as a native species. As the name suggests, they like a natural pond as opposed to lakes and rivers and like to spend a lot of time on land and bask for large portions of the day, giving them their other name – European Pond Tortoise, although they will also indulge in a good swim. They are accomplished climbers, so this will need to be factored in to keeping them contained as they do like to roam, especially the males. An amorous species, it is advised to make sure that the females well outnumber the males in a group. You may be lucky enough to encourage natural reproduction as has been observed in other UK gardens in recent years. I would not mix this species with other species.
If we look further afield, we need to look at species from similar climates to ours. Pseudemys rubriventris – Northern Red-bellied Cooter and clemmys guttata – Spotted Turtles both live in the northern reaches of the United States of America and can be found as far north as southern Canada in the case of Spotteds. Both are great species for UK ponds but have different requirements. Northern Red-bellied Cooters grow extremely large, females easily reaching 14” straight carapace length. They live in rivers and lakes in their natural range and in the garden must be provided as large and deep a pond as possible, with maybe only one or two specimens. Don’t be fooled by the cute green turtle they start off as, they grow very quickly if kept warm. The reward is a huge docile turtle with a dark, nearly black carapace and bright red plastron interspersed with black. Their herbivorous nature will make short work of any plants in the pond but tends to make them a tamer species and will even hand feed from their owners.
Spotted Turtles are almost the opposite of the Cooter’s, they are one of the smallest turtle species growing to only 5 inches straight carapace length. They are a marginal species, living in marshes and amongst the plants, therefore, they are suitable for a much smaller shallower pond which is more heavily planted. You will be able to keep a larger colony of these small black turtles with their bright yellow spots, a shy but docile creature. They will give you hours of pleasure trying to spot them amongst the lilys and iris. Rare and desired by collectors. Easily stressed, this species is best kept only with members of its own kind.
The final species I will discuss are chrysemys picta ssp the Painted Turtles. There are four subspecies of painted turtles in the United States which are named according to their range. C.p. bellii – Western Painted Turtle, c.p.picta – Eastern Painted Turtle, c.p.marginata – Midland Painted Turtle and c.p.dorsalis – Southern Painted Turtle. Other than the location they can be found in, they differ in appearance and size.
Western Painteds have a green carapace interspersed with red lines, a red plastron with heavy black blotching. Eastern Painteds have a plain yellow plastron, black carapace with horizontal scutes and yellow blotches either side of the head. They have bright red marginal scutes and lines on their legs. Midland Painted are visually like a cross between Western and Eastern and take the most beautiful aspects of both. Southern Painted Turtles swap the red for orange and have an olive coloured carapace with yellow plastron and a bright orange dorsal stripe running the length of the spine. The largest of these species, the Western Painted, generally grows to around 8 inch length and the smallest, the Southern, grows to around 6 inches.
Although the range of these four species is distributed widely across the United States – it is actually a genetic trait, rather than their locality, that makes them suitable for the UK. C.picta have a natural anti-freeze in their blood, meaning they can withstand below freezing temperatures and seem to be very tolerant of our cooler climate. Some worry about the Southern subspecies withstanding our winter, but I have had great success with hibernation, as have other keepers in the UK, with c.p.dorsalis.
All four subspecies are suitable for properly set up UK ponds and their smaller size and cocky nature makes for entertaining and manageable pets. Although they are very herbivorous, they are small enough not to decimate the plants in a garden pond.
Many people want to keep their turtles outdoors in their UK garden, to enjoy the tranquillity of the pond and witness their pets basking around the edge as they would in the wild.
Fortunately, there are species of turtles that can live in our climate.
This page discusses how we can keep turtles outside in the UK. There are some important factors to consider –
· The space you have available
· The positioning of your garden
· The species of turtles you will add to your pond
· The kind of pond you want and its construction
Adult European Pond Turtle
There are plenty of people in the UK who keep other species of turtles in garden ponds, and anecdotes of feral turtles living in lakes and canals. Often these species are Sliders (Yellow-Bellied, Red-Eared or Cumberland) trachemys scripta ssp or Map Turtles graptemys pseudogeographica. Some will have success with these species, others will not. I have a False Map Turtle adult female that happily stays out year round, I have had less success with my Sliders. Often survival will depend on whether you picked up a northern or southern variety of the animal, or their care before you got them. In any case, it’s a gamble. It’s worth remembering that some turtles can SURVIVE in the UK, they don’t THRIVE.
You may add some more warmer loving species, such as pseudemys nelsoni or malaclemys terrapin during the few hot months we have but bring the back in for autumn.
European Pond Turtle
The first thing you need to do is decide where to put your put pond. You need to have a garden that captures the sun for most of the day, turtles need to bask to maintain their body temperature. Avoid overhanging trees as leaf litter will decompose in the water and the shade will cool it. The shelter of a fence or wall can sometimes be beneficial as it will reduce wind chill.
Decide how you will construct your pond; will it be a flexible liner or a rigid preformed pond? There are ways of building ponds from block and brick which I don’t intend to discuss here.
Design your layout – this is important, do some drawings. Your turtles will want to swim, so design an open area of water. In the winter they need to go around two feet deep in order to hibernate, but in the spring they will be weak and sluggish and will need a slope to walk up, rather than a straight swim towards the surface. Create shallow shelves for planting. A shallow area is also useful as it will heat up more quickly in the sunlight. You may want a pond which is level to the ground, or a raised pond enclosed by sleepers or brickwork.
Choose your position
Mark your area out using string or spray paint and get digging! Use a pickaxe to break up hard ground and a shovel for the loose soil. Save the soil for later on a tarpaulin as you will need it for levelling and back fill.
If you are using a flexible liner you can make the pond any shape you like, which is useful. There is a chance the turtles could break the liner with their claws, but it isn’t something I’ve experienced.
If you are using a rigid pond you will need to dig the hole to the shape of the liner to ensure it sits correctly, but also has even support all round.
Use string or paint to mark out your pond
Once you have dug your hole you need to make sure there are no protruding sharp rocks or roots, as these will puncture your liner, even rigid ones. Once these are clear add a deep layer of builders sand on top of the soil for extra protection.
Use the soil you extracted, minus sharp stones, to level the edges of the pond. Take time with this as no garden is exactly level and if you have only an inch height difference either side, or end to end, you will expose liner on the higher side and this will give you dissatisfaction.
Use a long plank of wood and spirit level to meticulously check all sides and edges in different directions until you have it right.
It's important to use small unpaid workers and drink plenty of tea
Now you can add your liner. If this is a preformed one, it will simply slot straight in. Don’t expect to get this right the first time! There may be a lot of removal of the pond and subsequent removal or addition of sand and soil until you get a good, tight, level fit.
If this is a flexible liner make sure you have the size right. The size of the liner should be Width - (width of the pond + the depth of the pond + an additional 18” to 24” for an over lap) x Length (length of the pond + the depth of the pond + an additional 18” to 24” for an over lap). Always better to go too big than too small. Lie the liner flat over the hole, don’t push the liner into it. Weight the edges with rocks and place a hose pipe in the centre of the liner. Turn the water on and start to fill, the weight of the water will take the liner down and make a nice snug neat fit.
Once it is full (this is the test for the levelling…) you can trim your excess liner away. Leave at least 6 to 8 inches of overlap. Cover with your desired flagstones or turf to make the edges look neat.
Remember, it is unlikely that the ground is level. Trust your spirit
Filtration is essential in a garden pond as they lack the flowing water of naturally occurring feeder streams. Filtration takes harmful particles from the water, but also agitates the surface which creates and oxygenating effect. Without this, hibernating turtles will suffocate under the water and die.
There are several types of filters out there, the most common are pressure filters or box filters. Pressure filters are easier to conceal and also connect to other features like waterfalls. Box-filters tend to have a better filtration effect but can be unsightly. Both of these filters will need to be fed by an electric pump which sits within your pond.
Heating turtle ponds is not necessary.
Adding plants or not is up to you, I prefer a natural look and they improve water quality by taking nitrates from the water and releasing oxygen. Some species of turtle may be destructive to plants, so that is a consideration.
I add a layer of playsand to the bottom of the pond as a substrate for burying in, as well as some hiding areas like upturned plastic baskets or ridge tiles.
You must provide some sort of escape-proof fencing around the pond. Turtles will wander if not kept in. If you are using wire mesh than make sure the top of the fence has an overhang as turtles climb surprisingly well.
Allow your water to naturally reach the correct temperature for a few days before you add your turtles.
Pressure filters can be easily hidden
This is an important question, and it can mean life and death for your turtles. If you have acquired your turtles as hatchlings, then I strongly recommend raising in an indoor aquarium until they are a good size, at least 4 inches long. This may mean a year or two depending on the species. Before you put them outside, start to acclimatise them by turning off any aquarium heaters you may have.
Wait until the weather is consistently warm, days normally around 20°c, and choose a particularly warm day for your release. Don’t be fooled by the warm snap we sometimes have in March or April, I would be waiting until at least late May or June. If you have a cold spell after releasing your turtles, this can kill them.
Place them near the edge of the pond at the shallow end, and let them make their own way in. They may submerge quickly and you may not see much of them after this. They will hide a lot to start with, remember they may have never seen the sky before! Don’t worry about this, they will become bolder with time.
emys orbicularis basking on a log in a garden pond
Keep an eye out for excessive basking and sluggish turtles, particularly in spring and autumn, as this is a sign of sickness. Ill turtles should be brought inside and nursed back to health, this will normally require a vet visit.
Herons and other predators may take your turtles, it doesn’t seem common but guls and crows, as well as foxes and rats may show an interest.
Hibernation is a whole other subject and will be covered elsewhere.
A young chrysemys picta dorsalis getting some sun