| 1 | Boomslang |
Maximum length: 2.1 metres.
A garden is supposed to contain flowers, deck chairs on patios, rows of tomatoes, and perhaps a greenhouse. But something you’re just as likely to have if you live in Africa is a boomslang.
The boomslang (Dispholidus typus) inhabits over 15 countries in sub-Saharan Africa, from Ghana in the west to Kenya in the east. This is undoubtedly one of the deadliest snakes to show up in gardens worldwide. With an LD50 toxicity rating of 0.07mg, they almost match the black mamba (0.05mg) for sheer venom potency.
The boomslang’s venom is hemotoxic to the extreme, causing tiny cuts to burst open like an uncorked dam, and internal organs to start disintegrating. Fortunately, they struggle to inject venom due to awkwardly positioned fangs, and they have a small venom yield of only 1.6-8mg per bite.
Boomslangs are a great risk in gardens because of their strong tendency to disguise themselves in green foliage. This is a natural tree snake, but one which avoids dense forests, and prefers their bushy outskirts just adjacent to forest clearings. This makes a manmade garden absolutely perfect for them, as it’s a close mimic of their natural environments. Playing ball, throwing it into a bush, and sticking your arm in could easily result in a boomslang bite in Zimbabwe or Kenya.
| 2 | Common bronzeback |
Maximum length: 169cm.
A thin snake which rests on low branches and bushes, with a light weight in order to avoid snapping them. While the painted bronzeback is in total control of Thailand, common bronzebacks (Dendrelaphis tristis) are the ruling species of India.
Common bronzebacks are mildly venomous, a venom which is barely researched, but probably causes a mild swelling at most. This species is a common sight in rural gardens, particularly on bushes 1-2 metres above ground.
Common bronzebacks have many options, as they can pass through your garden, staying for only 5 minutes, or they can set up a base for several days, if they detect an abundance of hidden prey. This species preys on reptiles like agamids and geckos, and inhabits all of India except the towering Himalaya and drier northwest.
Common bronzebacks simply love gardens, and the scientific reason is that house gardens are a perfect replica of their natural habitat. Like the boomslang, common bronzebacks naturally live in forests, but particularly forest edges, with a mixture of bushes, grass, and thinner tree clumps. When a retired Indian man builds his dream garden, proudly applying the finishing touches, he has no idea that he’s created the perfect haven for this mildly venomous snake.
| 3 | Central American coral snake |
Maximum length: 115cm.
Mainly a forest snake, but far more flexible than the average coral snake, allowing them to appear in plantations and village gardens. Beware, as this is a dangerously venomous species, whose lethal toxin mixture far outstrips the common bronzeback’s.
Central American coral snakes (Micrurus nigrocinctus) appear in 9 confirmed countries, ranging from southern Mexico to western Colombia. Like most coral snakes, they have a powerfully neurotoxic venom, which can trigger paralysis and respiratory failure.
This can be a particularly dangerous species in gardens, as coral snakes love to lurk under cover, even burying themselves in shallow layers of soil and leaves. Gardeners rummaging around are at high risk of being bitten on the fingers, in Panama, Costa Rica and Nicaragua alike.
If your home is in a rural area directly adjacent to a forest, the risk dramatically increases. Central American coral snakes prefer forests, but regularly stray to their bushy outskirts. The same is true for the red-tailed coral snake of Colombia, or small coral snake of Trinidad. If your garden is next to a forest, then you’ll be highly vulnerable to the dreaded spillage effect. Even town gardens aren’t free from these dangerous serpents, as Venezuelan coral snakes have found been found in Caracas itself.
| 4 | Madagascan ground boa |
Maximum length: 320cm.
The thick, crushing constrictor of northern Madagascar, found in woodlands with an abundance of dried leaves to blend with. This species feeds on mammals, including brown lemurs and invasive rats.
We know that this species likes gardens, as the heaviest Madagascar snake of all time was found in a garden – the grounds of Anjajavy l’Hôtel in northern Madagascar. This was a Madagascar ground boa dubbed “Big George”, which measured 270cm and weighed 8.2kg.
This had lived peacefully among the guests and staff for years, the owner told the scientists, thus proving that a sudden Madagascan ground boa in your garden isn’t cause for panic. There’s no reason to be concerned, even if you’re stepping over them every morning. The only risk might be to your pets, as Madagascan ground boas won’t hesitate to swallow up a family cat.
Madagascan ground boas are officially the longest snake in Madagascar. They have fantastic camouflage, which even spreads to their eyes. They blend so effectively with fallen leaves that they can be completely invisible at the back of your garden, despite a thick tree trunk of a body.
| 5 | Yellow-striped trinket snake |
Maximum length: 180cm.
A non-venomous, yet energetic species which is common in southern Thailand, peninsular Malaysia and Sumatra. The yellow-striped trinket snake (Coelognathus flavolineatus) is fast-moving and possess a variety of skills, including swimming and climbing trees with aplomb. They mainly stick to the ground, and should be picked up with caution, as they possess a jagged pair of fangs which can easily tear human flesh.
Yellow-striped trinket snakes can appear in forests and fields alike, and gardens certainly aren’t off limits, including near the tourist city of Phuket in southern Thailand. If there’s a mixture of juicy vegetation and prey, then Coelognathus flavolineatus will happily settle down into your garden, or add it to a list of locations it returns to again and again, finding its way back using subtle scent particles.
The yellow-striped trinket snake could shock you in many ways. You could be adding an armful of grass cuttings to the pile, only for a serpent head to pop out. You could be picking tomatoes when a trinket snake falls out of the adjacent tree. You could be playing frisbee with your dog, and get bitten on the hand while retrieving it from a bush. The possibilities are endless with this garden-loving snake.
| 6 | Deuve’s kukri snake |
Maximum length: 53cm.
A Vietnamese species which was only confirmed as independent in 2016, after being split from its cousin the striped kukri snake. Deuve’s kukri snake (Oligodon deuvei) inhabits national parks like Cat Tien near Ho Chi Mingh City, including forests, but also back gardens, where they mainly stick to the ground.
Deuve’s kukri snake has dull colours, with a yellow-speckled stripe down its spine. A pond in your garden is a surefire magnet for Deuve’s kukri snake, if it’s teaming with tasty frogs. This species is non-venomous, but with their razor sharp fangs, this doesn’t prevent them from doing damage.
If you spot Deuve’s kukri snake in your garden, it’s not just a fun event, but an opportunity. Being so recently discovered, this is a species with large gaps in the scientific record – diet, predators, time spent on branches. Grab a notepad, a cup of tea, and you could be the first person on Earth to became an expert on Deuve’s kukri snake.
In 2019, for example, the California kingsnake was observed taking part in a 4-snake wrestling match, in a scientist’s own back garden. Who knows what you could observe with Oligdon deuvei, or any snake on this list.
| 7 | Common garter snake |
Maximum length: 137.2cm.
This harmless US species measures 80-100cm, and possess only the mildest possible venom. Common garter snakes live in streams and moist countryside fields, but regularly pop up on peoples’ back lawns, as these are a close match for their natural habitats. They inhabit all 48 lower US states except Arizona, and are a garden snake candidate virtually anywhere, including southern Canada. Even their name is theorised to be connected, as the word garter may originate from the German word of Garten for garden.
Common garter snakes are lured to people’s back gardens by the earthworms, slugs and leeches living there. These form a large portion of their diet, with larger meals including frogs. The sight of them slithering openly along flowers and bean stalks is probably too much to resist, and they do you a service by swallowing them up. The rest of the time, they rest harmlessly in the grass or swim in your pond.
Is there a chance of accidentally unearthing a common garter snake as you rummage around in long grass? Yes. Will they murder you for disturbing them? No.
| 8 | Grenada tree boa |
Maximum length: 188cm.
One of the most flexible boas in the Caribbean. The Grenada tree boa (Corallus grenadensis) can cling to trees outside hotels, by banana plantations, and most definitely in your garden.
Grenada tree boas inhabit their namesake island exclusively. They belong to the same Corallus genus as the emerald tree boa, but are infinitely more flexible in their habitats. They prey on rodents, so they won’t solve your backgarden slug problem, but they could solve your rat problem.
Grenada tree boas are common in rural gardens on this Caribbean island, where they can lurk silently for hours, usually disguised by overlapping tree branches. Through long and thick, they could still catch you unawares, hissing and lunging, forcing you to drop your grass cuttings and head indoors.
Grenada is an old colonial island, and is full of many large mansions and estates even today. Consequently, the Grenada tree boa is one of the few snakes on Earth that might well hang out in a twisting, confusing hedge maze, like something out of a horror film. They could lurk silently around corners, waiting for humans, making it twice as terrifying for the visitors lost in its winding passages, particularly if a sudden mist arrives from the ocean.
| 9 | Red-lipped snake |
Maximum length: 89.1cm.
A common snake in suburban areas of South Africa. The red-lipped snake is secretly one of sub-Saharan Africa’s most common snakes, ranging from Gambia on the Atlantic coast to Tanzania adjacent to the Pacific, covering well over 20 countries.
Red-lipped snakes like relatively moist areas, appearing in forests, marshes, and quite often, random people’s backgardens. Toads are one reason, as red-lipped snakes have the power to swallow huge ones. Rain frogs are one confirmed prey, and red-lipped snakes can track them simply by following scent particles, meaning that a garden full of amphibians is bound to attract them soon or later.
If your garden backs onto a desolate canyon, then this species won’t turn up, but if it’s a traditional garden of flowers and beans and ponds, then don’t be surprised to find one. Red-lipped snakes are famous for their skill to triangulate their head, meaning that you might mistake them for a viper
This species certainly isn’t deadly, but the exact potency of its venom is unknown. If you find a red-lipped snake chewing your hand after doing some gardening, then remove it as fast as possible.
| 10 | Hudson’s coffee snake |
Maximum length: 49.4cm.
An Ecuadorian species, with no venom and an average length of 40-50cm. Hudson’s coffee snakes (Ninia hudsoni) are very timid, and normally shield their brain in their coils when picked up. On the eastern slopes of the Andes, you have a strong chance of meeting them, as while they generally prefer evergreen forests, they’re also plentiful in gardens and pastures.
Hudson’s coffee snakes stick to the ground rather than climbing trees, so you may find them under assorted objects. It’s possible that they’re hiding in your garden to avoid coral snakes, as Hemprich’s coral snake is one of their confirmed predators.
Rather than a curse, this species is a blessing. Hudson’s coffee snakes feed on worms and grubs that nibble at your produce, increasing the yield, preventing rotten and useless ones, whether it’s strawberries or tomatoes.
If you want to own the most productive, vibrant garden in town, then a Hudson’s coffee snake is one way to achieve it – maybe 5 or 6. If you hold your nerve, and accept that a snake colony lives right outside your backdoor, they could turn you into a master gardener.