Garter Snake (Thamnophis sp.)
Garter snakes and ribbon snakes (Thamnophis sp.) are a terrestrial genus of snakes that can be found all over North and Central America. Garter snakes come in many different varieties (there are around 35 recognized species!), but they are generally found in fields, forests, wetlands, marshes, and residential areas near bodies of water. Garter snakes are best known as accomplished swimmers, but they are also known to occasionally climb as needed.
Because of the variety of species, garter snakes vary widely in length. Here is a compilation of garter snake and ribbon snake species commonly found in captivity, as well as their lengths. The following information is sourced from Garter Snakes: Their Natural History and Care in Captivity by Roger Sweeney:
- Short-headed garter (T. brachystoma): <22″ / 56cm
- Butler’s garter (T. butleri): <27.5″ / 70cm
- Aquatic garter (T. couchi): 18-57″ / 45-145cm
- Sierra (T. c. couchi)
- Coast (T. c. aquaticus)
- Santa Cruz (T. c. atratus)
- Giant (T. c. gigas)
- Two-striped (T. c. hammondi)
- Oregon (T. c. hydrophilus)
- Black-necked garter (T. cyrtopsis): <43″ / 110cm
- Western (T. c. cyrtopsis)
- Eastern (T. c. ocellatus)
- Southern (T. c. fulvus)
- Western terrestrial garter (T. elegans): <42″ / 106cm
- Mountain (T. e. elegans)
- Klamath (T. e. biscutatus)
- Coastal (T. e. terrestris)
- Wandering (T. e. vagrans)
- Mexican (T. e. errans)
- Mexican garter (T. eques): <40″ / 102cm
- Common (T. e. eques)
- Northern (T. e. megalops)
- Durango (T. e. virgatenius)
- Checkered garter (T. marcianus): <42.5″ / 108cm
- Northern (T. m. marcianus)
- Southern (T. m. praecularis)
- Northwestern garter (T. ordinoides): <26″ / 66cm
- Western ribbon snake (T. proximus): <48″ / 123cm
- Western (T. p. proximus)
- Arid Land (T. p. diabolicus)
- Gulf Coast (T. p. orarius)
- Red-striped (T. p. rubrilineatus)
- Plains garter (T. radix): <40″ / 102cm
- Eastern (T. r. radix)
- Western(T. r. haydeni)
- Narrow-headed garter (T. rufipunctatus): <34″ / 87cm
- Eastern ribbon snake (T. sauritus): <40″ / 102cm
- Eastern (T. s. sauritus)
- Blue-striped (T. s. nitae)
- Peninsula (T. s. sackeni)
- Northern (T. s. septentrionalis)
- Common garter (T. sirtalis): 20-51″ / 50-130cm
- Eastern (T. s. sirtalis)
- Texas (T. s. annectans)
- Red-spotted (T. s. concinnus)
- Valley (T. s. fitchi)
- California red-sided (T. s. infernalis)
- New Mexico (T. s. dorsalis)
- Maritime (T. s. pallidula)
- Red-sided (T. s. parietalis)
- Puget Sound (T. s. pickeringi)
- Chicago (T. s. semifasciatus)
- Blue-striped (T. s. similis)
Although there are many different species and subspecies of garter snake, they generally have a similar appearance: big round eyes, slender build, keeled scales, and stripes running the length of their bodies. In some cases, they may have speckling instead of or in addition to their stripes. Garter snake coloring can be as drab as gray-brown or as striking as red and blue.
Despite being some of the most common snakes in the United States, garter snakes and ribbon snakes are not very common in the pet trade. They can make great pets, however! They’re manageably-sized, fairly hardy, and even tolerate being housed in groups. With good care, garter snakes can live 10 years or more.
Note: Some garter snake subspecies are federally protected and illegal to keep in the United States.
Garter Snake Shopping List
These are products I personally recommend for setting up a functional generic ribbon snake or garter snake enclosure. Some of the links in this care sheet are paid links — if you’d like to know why ReptiFiles uses paid links, visit this page.
- 48”L x 24”W x 24”H reptile enclosure, front-opening
- Zoo Med Combo Deep Dome Dual Lamp Fixture
- 50w Arcadia Halogen Heat Lamp, x2
- Zoo Med ReptiTemp Rheostat
- Flat basking stone
- Zoo Med Digital Combo Thermometer Humidity Gauge, x2
- 22″ Arcadia Forest 6% OR Zoo Med T5 HO Reptisun 5.0 UVB bulb
- 24″ Arcadia ProT5 OR Vivarium Electronics T5 HO fixture
- Exo Terra Mister
- Zilla 24/7 Digital Power Center
- Zoo Med Eco Earth, 40+ quarts
- Reptile hides/caves, at least 2 (small enough to provide a tight squeeze)
- Plastic tub, 16″ x 13″ x 6″ or similar (ex: Container Store Sweater Box)
- Environmental enrichment items
- Repashy Calcium Plus
- 12″ feeding tongs
Garter Snake Enclosure Size
Garter snakes are active snakes that love to explore, and are enthusiastic climbers and swimmers, so although they may seem small because of their slender build, they still need plenty of room to accommodate their preferred lifestyle. As a generalization, the minimum enclosure size for one average garter snake is going to be 48”L x 24”W x 24”H. This is based on the formula for calculating a snake’s minimum space needs:
snake length x half snake length x half snake length = length x width x height
At ReptiFiles, using a larger enclosure than the minimum is always strongly recommended. Bigger is always better! Here are some enclosures that ReptiFiles recommends for housing garter snakes, based on the snake’s expected adult length:
3′ long or less:
- Custom Reptile Habitats 3 Foot Reptile Enclosure
- Exo Terra 36″ x 18″ x 18″ All-Glass Terrarium
- Carolina Custom Cages Large 36″ x 18″ x 18″
- Repti Zoo 36″ x 18″ x 18″ Reptile Terrarium
- Custom Reptile Habitats 4 Foot Reptile Enclosure
- Zen Habitats 4’x2’x2′ PVC Panel Reptile Enclosure
- REPTIZOO Large Glass Reptile Terrarium 48″ x 24″ x 24″
- Carolina Custom Cages Terrarium, Tall Extra-Long Deep 48Lx24Dx24H
Whichever you choose, make sure it’s EXTREMELY well-proofed against escape! Garter snakes are small and flexible, which means that they are essentially professional escape artists. If you are raising a juvenile or few, this is especially important. Front-opening enclosures with very tight seams and swinging doors are the most secure, such as Exo Terra’s line of terrariums.
Can multiple garter snakes be housed together?
Although the vast majority of snake species do best when housed singly, garter snakes are a possible exception! While garter snakes have been known to do well by themselves, they can also be housed in groups, and group housing seems to be particularly beneficial for decreasing stress in juveniles. Of course, more inhabitants means more space will be required to keep everyone comfortable: if you’re keeping more than two together, you’ll need to significantly increase the size of the enclosure.
Do pay attention to the sex of any garter snakes you’re interested in housing together, however — since garter snakes are livebearers, if you house a male and female together, you’re likely to eventually get surprised with lots of little babies!
As an additional note: certain species are somewhat prone to cannibalism, and shouldn’t be cohabited as a safety precaution.
- Wandering garter (T. e. vagrans)
- Checkered garter (T. marcianus)
- Coast garter (T. e. terrestris)
- Common garter (T. sirtalis)
Lighting & UVB for Garter Snakes
As a general rule, lights should be on for 14 hours/day during summer and 10 hours/day during winter, with gradual adjustments in-between. Alternatively, you can sync your lights to local sunrise and sunset times using smart timers like the Kasa Smart Power Strip.
For safety and convenience of placement, it’s preferable to install all lamps on top of the enclosure, over a mesh top, rather than inside.
UVB lighting has also been proven to be beneficial to snakes’ health. So although garter snakes can technically survive without UVB, we strongly recommend providing it in order to promote optimum welfare in captivity.
UVB lighting can be tricky, because in order to get the right strength of UVB (UV Index, or UVI), distance and potential mesh obstruction must be considered. To provide appropriate UVB for a garter snake, you will need a Zoo Med T5 HO Reptisun 5.0 or Arcadia T5 HO Forest 6% bulb, long enough to span half of the enclosure and placed on the warm side of the enclosure.
The basking branch or platform should be placed according to the following, with distance being measured between the UVB lamp and the height of the snake when on the basking surface.
- With mesh obstruction: 9-12”
- Without mesh obstruction: 12-14”
(These recommendations are approximations based on available data. For best results, use a Solarmeter 6.5 to determine the best placement to achieve a UVI of 2.0-3.0 in the basking area.)
Garter snakes are significantly active during daytime, which means that providing bright illumination during the day is likely to be beneficial in stimulating activity and natural behaviors. You will need a nice bright 6500K LED or T5 HO fluorescent grow light, long enough to span most of the enclosure’s length. Some of my favorite options:
These lamps are also essential for supporting any live plants you may have in the setup.
Garter Snake Temperature Requirements
Humans are warm-blooded, which means that our body temperature is automatically regulated. Garter snakes, however, are cold-blooded, which means that they have to move between areas of different temperatures in order to regulate their body temperature. Garter snakes typically warm up by basking in warm patches of sunlight. In captivity, using a halogen flood heat bulb is the best way to replicate the type of warmth provided by sunlight.
- Basking area: 85-90°F (29-32°C)
- Cool side: 75-80°F (23-27°C)
- Nighttime: 64-75°F (18-24°C)
Specific optimal basking temperatures may vary by which garter or ribbon snake species you’re keeping, as some are native to areas that are warmer than others. Note that general air temperatures (cool side temperatures) above 91°F / 33°C are considered dangerous and may cause heat stress and, if unresolved, death by heat stroke.
Heat sources should be turned off at night. During winter, temperatures can be reduced to 60-68°F / 16-20°C in daytime.
Generally speaking, 50w halogen flood bulbs should be plenty to achieve your target basking surface temperature. The basking rock should be placed on top of the black plastic hide box, which will act as your warm hide. If you notice that they’re getting too hot, dial it down with a plug-in lamp dimmer. If your basking surface is too cool, you need higher wattage bulbs.
You will need multiple heat bulbs to create a large enough basking area to evenly heat your snake’s coiled body. Two bulbs is enough for an adult garter snake. Create a warm hiding place for the snake to use by placing a black box hide under the heat lamps, with a flat basking stone on top.
To measure the temperatures around your enclosure, use digital probe thermometers — one placed on the basking surface and one on the cool end of the setup. Most reptile-brand digital probe thermometers function well.
Garter Snake Humidity Requirements
Garter snakes generally need an average humidity of 35-60%, as measured by a digital probe hygrometer with the probe placed in the middle of the enclosure. Humidity levels that are consistently higher or lower than this range can make your pet unwell, although it is normal for humidity to be higher on the cool end and lower on the warm end, as well as higher at night. Specific optimal humidity levels may vary by which subspecies you’re keeping.
To raise humidity in your snake’s enclosure, you can use a pressure sprayer to mist the habitat as needed. It’s also a good idea to place moistened sphagnum moss inside the cool hide to create a humid retreat. Check and change this moss regularly to prevent mold growth. Placing a layer of leaf litter on top of the substrate can also help maintain humidity.
How to create a swimming area for garter snakes
Garter snakes naturally live near bodies of water in the wild, and although the amount of time they spend in the water varies by species, they are generally proficient swimmers. For this reason, it’s important to provide a basin of water on the cool side of the enclosure. A clear plastic storage bin or glass aquarium smaller than 20″L x 12″W x 8″H should be plenty.
Change out the water once weekly or whenever it gets soiled. Scrub the water dish with veterinary disinfectant such as Rescue or F10SC before refilling. Using a Python siphon makes emptying the basin easier.
Substrate Options for Garter Snakes
Garter snakes are healthiest and happiest when they are housed on a substrate (a.k.a. “bedding”) that imitates the conditions of their natural habitat and facilitates moderate humidity levels.
Here are some suitable substrate options for ribbon and garter snakes:
Shredded aspen may also be suitable in more humid climates, although it molds easily. Alternatively, you can use a DIY mix of 40% organic, additive-free topsoil + 40% Zoo Med Reptisoil + 20% play sand (this option tends to be the most affordable as well).
Provide a substrate layer that is at least 2” deep. For a 4x2x2 enclosure, that will take at least 40 quarts of substrate. I also recommend laying down a generous layer of clean leaf litter on top to help retain humidity and give your snake something to explore.
Feces and urates should be removed daily, and contaminated substrate should be scooped out and replaced. Substrate should be completely replaced once every 3-4 months.
Décor Ideas for a Garter Snake Enclosure
Decorations play an important role in your garter snake’s enclosure as environmental enrichment. Enrichment items encourage exercise, stimulate your snake’s natural instincts, and help promote overall wellbeing. And, of course, they make the enclosure look nice!
Environmental enrichment ideas for garter snakes:
The more hiding places your snake has access to, the more likely it will be comfortable hanging out in the open where you can see it. Hides should be small enough to provide a tight fit for the snake when coiled.
Feeding Your Garter Snake
Garter snakes are carnivores, which means that they need a diet of whole animal prey in order to get the nutrition that their bodies need. How often they need to eat can be estimated by age:
- Hatchlings — every 3-5 days
- Juveniles and adults — every 4-7 days
The size of your snake’s prey should be no more than 1.5x the width of your garter snake at its widest point, or up to 10% of its body weight. Note that due to caloric density, worm eaters need to be fed less frequently than fish eaters, and mouse eaters the least frequently. Worms and fish should be offered multiple at a time.
Wild garters are known to eat a variety of prey, including earthworms, leeches, fish, tadpoles, newts, frogs, young birds, and small mammals. In other words, the key to providing a healthy, balanced diet for your pet snake is VARIETY. Provide as varied of a diet as you possibly can, and you will be rewarded with a healthier, less picky pet!
Prey ideas for garter snakes:
- earthworms (chopped as needed)
- button quail
- quail eggs
Never use red wigglers as feeders, and nightcrawlers are best avoided. Use soft-tipped feeding tweezers to reduce the risk of getting accidentally bitten when the snake strikes.
If you are housing multiple garter or ribbon snakes together, it’s best practice to feed them separately to prevent accidental cannibalism.
Snakes can survive without vitamin or mineral supplements, but using them occasionally is a good way to help prevent nutritional deficiencies. Every once in a while, lightly dust the prey item with a 50/50 mix of calcium and multivitamin before thawing.
Handling Your Garter Snake
You will need to wait a little while after bringing your new pet home to let it settle in. This usually takes about 2 weeks, but you shouldn’t start handling until it’s eating regularly.
Once your garter snake is ready for handling, take it slow at first. Start with brief handling sessions (no longer than 5 minutes), and don’t return the snake until it is calm. This teaches your pet how to behave during handling by using rudimentary positive reinforcement. Once this has been accomplished, you can work up to longer sessions. Handling should occur at least weekly, but no more than once daily.
While handling your snake, be gentle. Rather than grabbing it, let it crawl onto your hand. Lift it from below rather than above, and support as much of its body as possible, as garter snakes are quick-moving and they don’t cling to your fingers and hands like constrictors do. Use slow movements and don’t walk around too much.
Garter snakes usually tolerate handling well by the time they’ve reached adulthood, although individuals vary, and some will always prefer to be left alone.
Baines, F. M., Chattell, J., Dale, J., Garrick, D., Gill, I., Goetz, M., Skelton, T., & Swatman, M. (2016). How much UVB does my reptile need? The UV-Tool, a guide to the selection of UV lighting for reptiles and amphibians in captivity. Journal of Zoo and Aquarium Research, 1, 56. https://doi.org/10.19227/jzar.v4i1.150
Benfer, Jeff. “Garter Snake Care Sheet.” Reptiles Magazine, 8 July 2014, https://www.reptilesmagazine.com/garter-snake-care-sheet/.
Crowe, Jonathan. “Garter Snake Care Guide.” Gartersnake.info, http://www.gartersnake.info/care/. Accessed 17 June 2021.
“Low UV Species.” Arcadia Reptile, https://www.arcadiareptile.com/lighting/low-uv-species/. Accessed 17 June 2021.
Mede, Erica. “Garter Snake Care.” Chicago Exotics Animal Hospital, http://www.exoticpetvet.com/garter-snake-care.html. Accessed 17 June 2021.
Sweeney, Roger. Garter Snakes: Their Natural History and Care in Captivity. Blandford Press, 1992.
Kousebandslangen.nl, http://www.kousebandslangen.nl/thamnophis/wp-content/uploads/How-to-take-care-of-garter-snakes.pdf. Accessed 17 June 2021.
The ReptiFiles Garter Snake Care Sheet is a simplified care summary, not a full ReptiFiles care guide. While I have done my best to ensure that the information contained is accurate, due to time constraints, the research behind ReptiFiles care sheets is not as thorough as the research involved with my full-length care guides. I strongly encourage readers to do their own research from high-quality, reputable sources outside of just this care sheet as part of preparing for your new pet reptile.