A sundew plant looks like it has been rolled in glitter. Every leaf is studded with tiny tentacles, and each tentacle holds a bead of sticky, glistening fluid that catches the light like morning dew. That is where the name comes from, and that is also the trap. Insects mistake the shimmer for water or nectar, land for a sip, and find themselves glued in place while the leaf slowly curls around them.
There are close to two hundred species in the genus Drosera, scattered across nearly every continent, from cold northern bogs to warm South African hillsides to the seasonal wetlands of Australia. That range is exactly why so many new growers struggle. People treat a sundew like a single plant with a single set of rules, when in reality “sundew” is a sprawling family of plants with one shared trick and several very different lifestyles. Get the right type for your conditions and match a few non-negotiable habits, and a sundew is honestly one of the easier carnivorous plants to keep alive. Get the type wrong, or water it like an ordinary houseplant, and it will be dead within weeks.
This guide walks through everything that actually keeps a sundew thriving indoors: the water it demands, the mineral-free soil it needs, the light that turns it red and dewy, how and how often to feed it, the dormancy question that trips up half of all beginners, how to make more plants for free, and how to read and fix the handful of problems that come up.
A Sundew Is a Bog Plant That Eats Insects Instead of Fertilizer
Understanding where sundews come from explains almost every care instruction that follows. They grow in bogs, fens, and seasonal wetlands, where the soil is permanently wet, intensely acidic, and stripped of nutrients. The ground in these places holds almost no nitrogen or minerals, so over millions of years sundews evolved a workaround. Rather than pulling nutrients up through their roots, they catch them out of the air.
Each leaf is covered in trichomes, the stalked tentacles tipped with a gland that oozes mucilage, the sticky sap that forms those signature dewdrops. When a small insect lands and sticks, the plant senses its struggle and begins a slow bending motion called thigmonasty, folding the tentacles, and sometimes the whole leaf, inward to wrap the prey in more glue and more glands. The leaf then releases digestive enzymes that break the insect down into nutrients it can absorb directly through the leaf surface. Mosquitoes, fungus gnats, fruit flies, aphids, and other soft-bodied insects make up the bulk of the diet, with larger species able to handle larger prey.
Two consequences fall out of this biology, and they are the backbone of sundew care. First, the plant gets its nitrogen from bugs, not from soil, so ordinary potting mix and fertilizer are poisonous to it. Second, because it is adapted to mineral-free water, the dissolved minerals in tap water act like a slow toxin. Nearly every sundew death among beginners traces back to one of those two facts.
Most species stay small. A mature rosette of a spoon-leaved or spatulata-type sundew might be only one to two inches across, while upright forms like the Cape sundew throw leaves several inches long, and a handful of giant and climbing species reach a foot or more. In spring and summer many send up a slender flower stalk well above the foliage, carrying small white, pink, or pale purple blooms. On a perennial sundew, flowering and setting seed does no harm, which is good news if you want to collect seed later.
Identify Whether You Have a Tropical or Temperate Sundew First
This is the single most important decision in sundew care, and it has to happen before you do anything else, because it changes how you handle the plant for half the year.
Tropical and subtropical sundews come from warm climates that rarely or never freeze, places like South Africa, Australia, New Zealand, and South America. They grow all year round and never need a cold rest. The Cape sundew (Drosera capensis) is the classic example, along with spatulata, natalensis, tokaiensis, binata, and adelae. These are the plants to grow indoors as year-round houseplants, and they are the ones beginners should start with. They forgive a great deal and ask for nothing more exotic than a bright windowsill or a shop light.
Temperate sundews come from cold-winter regions across North America, Europe, and northern Asia. The roundleaf sundew (Drosera rotundifolia), hardy through roughly USDA zones 3 to 8, is the best-known example. These plants are genetically programmed to shut down for three to four months of cold each winter. They die back to a resting bud or to the root crown, sit dormant, and resprout in spring. Skip that cold rest year after year and the plant slowly exhausts itself and dies, even though it looks fine for a while. Temperate species are rewarding but better suited to a cool windowsill, an unheated porch, or an outdoor bog garden than to a warm living room.
A smaller group of Australian and South African species reverses the calendar and rests in summer instead of winter. They are less common in cultivation, but if you buy one, look up its specific schedule.
If you bought your plant from a general nursery or hardware store and it came with no name, assume it is most likely a Cape sundew or a spatulata, since those are the two most widely sold. When in doubt, identify the exact species before winter arrives, because that single fact tells you whether to keep it warm and growing or let it rest cold.
Water Only With Rain, Distilled, or Reverse Osmosis Water
If you remember nothing else, remember this. The minerals dissolved in ordinary tap water will accumulate in the soil and kill a sundew, often slowly enough that the cause is never obvious. The plant evolved in water so pure it carries almost no dissolved solids, and it has no defense against the calcium, magnesium, sodium, and other minerals that municipal water and softeners add.
Use rainwater, distilled water, or reverse osmosis (RO) water for everything: watering, misting, and even the first rinse of your potting materials. As a rough rule, water below about 50 parts per million of total dissolved solids (TDS) is safe. Some growers in soft-water areas get away with tap water under that threshold, but the only way to know your number is to measure it with an inexpensive TDS meter, and even then the safe move is to default to pure water. Rainwater collected from a clean roof or barrel is the cheapest source, distilled jugs from the grocery store are the most convenient, and an RO unit pays for itself if you keep a collection.
Sundews are bog plants, so the soil must stay wet at all times and should never dry out completely. The standard method is the tray method: stand the pot in a shallow dish or tray and keep water in it so the plant drinks from the bottom. Fill the tray to about a quarter to a third of the pot’s height during active growth, refilling as the plant and evaporation draw it down. Tall pots can sit in water up to halfway. This keeps the root zone constantly moist without leaving the surface a soggy swamp, which matches how a bog actually behaves: a high water table below, but a damp rather than flooded surface.
One habit prevents a slow death even when you use pure water. Every couple of months, top-water the pot heavily so fresh water runs down through the soil and out the bottom, flushing any minerals that have crept up toward the surface through evaporation. If you ever use water at the upper edge of safe, this flush matters even more. With genuinely zero-ppm water, mineral creep is negligible and you can go far longer between flushes.
Build a Nutrient-Free Mineral-Free Soil From Peat, Sphagnum, and Sand
Never use regular potting soil, compost, garden soil, or anything with added fertilizer. The nitrogen and minerals in standard mixes will burn and kill a sundew quickly. A carnivorous-plant medium does the opposite of what most potting mixes are designed to do: it stays nutrient-poor, acidic, airy, and permanently moist.
You can buy a pre-made carnivorous plant mix, or blend your own from a short list of ingredients:
- Sphagnum peat moss: the standard base, acidic and water-retentive. Buy plain peat with no added wetting agents or fertilizer. It is dusty when dry, so rinse it before use, and avoid inhaling the dust.
- Long-fibered sphagnum moss (LFS): many sundews grow happily in pure LFS, and it is cleaner and faster to pot with than a peat-sand blend. A common approach is pure LFS or a loose mix of roughly five parts LFS to one part sand.
- Silica sand: pool filter sand or sandblasting sand, ideally a coarser grade around 0.5 mm, opens the mix up and improves drainage. Avoid mineral-rich play sand, and rinse the sand even if it is sold pre-washed.
- Perlite: lightens the mix and holds water, though it can encourage algae in stagnant, low-airflow setups, so use it where you have decent air circulation.
- Coconut coir: a peat substitute made from coconut husk, but it carries a high natural salt load. If you use it, soak and rinse it through several changes of pure water over a few days first to flush the salts.
A reliable all-purpose recipe is one part peat moss to one part rinsed silica sand or perlite. Whatever you blend, rinse every component with several changes of water, finishing with pure water, before potting. Peat, sand, perlite, and coir all carry minerals and fine particles that can leach into the bog you are trying to build.
Aim for a slightly acidic medium in the pH 5.0 to 6.5 range, which the peat and sphagnum naturally provide. A light top-dressing of live sphagnum or even pine needles helps hold acidity and surface moisture. Pack the soil a little firmer in the bottom quarter of the pot and looser toward the top, which wicks moisture evenly up to the crown.
Pot choice matters more than it seems. Sundews grow surprisingly deep roots for their size, an adaptation to reaching down to the bog water table, so a one-inch rosette may send roots four to six inches down. Give all but the tiniest seedlings a pot at least four inches deep, and six inches for adult Cape-type and other South African species. Use plastic or glazed ceramic pots. Avoid unglazed terracotta and clay, which slowly leach minerals into the soil over time.
Give a Sundew as Much Bright Light as You Can
Light is what makes a sundew look like a sundew. Strong light drives the production of mucilage, those sticky dewdrops, and it brings out the red, orange, and purple pigments in the tentacles. A sundew that is not getting enough light stops making good dew and fades to a flat, dull green, which is the most common early sign that something is wrong.
Aim for at least six to eight hours of direct or very bright light a day. A sunny south or west-facing windowsill works well for many species. Be aware that the brightest, hottest summer sun through glass can scorch some of the more delicate mountain species, so if you see leaves bleaching or burning in midsummer, filter the harshest afternoon light. The fork-leaf types and a few others actively want full sun, while many South African and South American highland species prefer strong light at milder temperatures.
If you do not have a bright enough window, artificial light works just as well and is more consistent. Plain LED or fluorescent shop lights in the range of 2,500 lumens or more do the job; specialty pink-and-blue “grow” diodes are not necessary and are harder on your eyes. Start the light about twelve inches above the plant and adjust based on how the plant responds, lowering it if growth is weak and pale, raising it if leaves scorch. Put the lights on a timer for a long photoperiod of roughly fourteen hours. A healthy plant under good light will color up and produce abundant dew within a few weeks.
Feed Insects, Never Fertilizer
A sundew makes its own meals from the air, so under no circumstances should you add fertilizer to the soil or the water. Fertilizer is one of the fastest ways to kill one of these plants. Feeding means insects, not nutrients in a bottle.
Indoors, where flying prey is scarce, a little hand-feeding speeds up growth and keeps a plant vigorous, though a sundew on a sunny sill will also catch its own fungus gnats and fruit flies. The easiest foods to handle are wingless or flightless fruit flies, freeze-dried bloodworms, and small betta-fish pellets, all of which you can find at pet and aquarium stores. Dried bloodworms and pellets should be rehydrated with a drop of pure water and placed gently onto the dew so the tentacles can grab them. A struggling live insect triggers the strongest response, but even a moistened crumb of suitable food works.
Portion size is the part beginners get wrong. The prey should be tiny, roughly the size of the insects the plant would catch naturally, and a leaf only needs a piece it can fully close around. Curling and digesting takes real energy, so overfeeding, or dropping on a chunk too large, can cause the leaf to blacken and die back instead of digesting. Feed young plants more often, perhaps once a week to once a month, to push them toward mature size, and feed established plants less, every few weeks to a couple of months. Frequent flowering and steady new growth are signs a plant is well fed; stalled growth and weak dew often mean it is hungry.
Manage Humidity and Temperature to Match the Plant’s Origin
Sundews are wetland plants and appreciate moderate to high humidity, but most adaptable houseplant species tolerate average indoor air better than their reputation suggests, especially once established and sitting on a constantly moist tray. The tray itself raises local humidity around the plant. In very dry rooms, grouping plants together or growing them in an open terrarium helps; a terrarium also makes a striking display, as long as it is deep enough for the roots and has a vent or open panel for airflow, since stagnant, saturated air invites mold.
Temperature needs follow the tropical-versus-temperate split. Tropical and subtropical species are comfortable in ordinary room conditions, broadly 70 to 90F in the warm season and milder but frost-free the rest of the year; protect them from anything below about 55F. Temperate species prefer cooler conditions overall, often happiest around 50 to 70F in the growing season, and they need a genuinely cold winter to rest. Whatever the type, keep plants out of cold drafts and away from blasting heat vents, and acclimate them gradually whenever you move them between very different conditions.
Handle Winter Dormancy Only If Your Species Needs It
Dormancy is where the tropical-versus-temperate distinction pays off, and where a lot of well-meaning care goes wrong in both directions.
If you grow a tropical or subtropical sundew, there is no dormancy to manage. Keep it warm, lit, and watered all year. Forcing a tropical species into a cold rest it never evolved to take can harm or kill it, so resist the urge to “give it a winter.”
If you grow a temperate sundew, the cold rest is mandatory for long-term survival. As days shorten and temperatures fall, the plant naturally slows, and many species die back to a tight resting bud called a hibernaculum or simply to the root crown. When you see that seasonal die-back, move the plant somewhere cold but not freezing, ideally between about 35 and 50F, such as an unheated garage, a cold porch, or even the back of a refrigerator. Through dormancy, reduce watering: keep the soil just barely moist rather than standing in a tray, and never let it dry out completely or freeze solid. Leave the plant cold and resting for roughly three to four months.
When dormancy ends, bring the plant back to warmth and light gradually over several days rather than all at once. As fresh growth pushes out, trim away the old browned leaves with clean scissors, and keep dead material dry, because soggy dead tissue is an open invitation to gray mold.
Make More Sundews From Leaf Cuttings, Division, and Seed
Sundews are famously easy to multiply, which is part of their appeal. Three methods cover almost every situation, and all of them rely on the same pure water and nutrient-free conditions as the parent plant.
Leaf cuttings are the simplest and most productive route. Even a small plant has plenty of leaves to spare. Cut a healthy leaf off at the base where it meets the central stem and lay it on a bed of wet long-fibered sphagnum or a thin carnivorous mix, pressing the cut end into contact with the surface. Cover with a humidity dome or clear lid to hold moisture, keep it warm at roughly 75 to 85F under bright light, and keep the medium constantly wet by misting or bottom-watering. Tiny plantlets typically appear along the leaf within one to two months.
Division suits plants that have formed clusters or sent out offshoots. Lift the plant, gently crumble the soil away, and separate the rosettes where they branch from the central stem, taking care with the deep, fine roots, which can run four inches even on a small plant. Pot each division into fresh carnivorous mix in its own deep pot, settle it on a moist tray under bright light, and it carries on with little fuss.
Seed works for any species and is the most reliable route for annual types, which complete their life in a single season and rely on seed to continue. The seeds are dust-fine, so handle them over a container to avoid losing them. Scatter them on the surface of moist carnivorous mix without burying them, since they need light to germinate, then cover to hold humidity and keep warm and bright. Most sprout within two to four weeks, and seedlings can reach maturity in as little as a few months for fast species. Unused seed keeps for years in a sealed bag in the refrigerator at around 35F. One caution: sundew seed is often pricier and slower than simply buying an established plant, so for a first plant, an adult is usually the better value.
Read and Fix the Few Problems Sundews Run Into
Sundews have fewer pest and disease issues than most houseplants, but a handful come up often enough to know in advance. Most trace back to mineral-laden water, too little light, or stagnant wet conditions.
No dew, dull green color, or stretched growth is almost always a light problem, occasionally a sign the plant is newly arrived and still adjusting. Nursery plants are often grown in humid, lower-light conditions and lose their dew from shock when moved; give them a few weeks in strong but not scorching light and the dew usually returns. If it does not, increase the light. Move plants between very different light levels gradually, since dumping a low-light plant straight into full summer sun can burn it in a single day.
Aphids can infest even a bug-eating plant, causing curled, discolored, or stunted leaves. Because sundew leaves are small and crowded, picking aphids off by hand is often impractical. A surprisingly effective fix is to submerge the whole plant, pot and all, in pure water for about a day, then drain it and let the soil return to normal moisture. Repeat if survivors appear, and follow with a light neem oil spray only if needed.
Fungus gnats are drawn to the permanently wet soil, where they lay eggs and their larvae chew on roots, causing wilting and root damage the plant cannot fight even as it eats the adults. A dusting of cinnamon on the soil surface smothers larvae and deters egg-laying, sticky traps catch the adults, and in stubborn cases beneficial nematodes or a Bacillus thuringiensis product clears the larvae. The best prevention is a well-drained mix and good airflow.
Gray mold (botrytis) shows up as fuzzy gray growth and brown or black spots, thriving where leaves stay wet in warm, still, humid air. While the soil must stay wet, the leaves themselves should not sit damp for long stretches, so improve ventilation, keep dead material cleared away and dry, and cut off affected parts with sterilized scissors, discarding them. Avoid fungicides where you can, as they can damage delicate sundew tissue.
Root rot is the one that feels like a contradiction on a bog plant, but it happens when soil goes from wet to truly waterlogged and oxygen-starved, often signaled by wilting, leaf loss, and a sour, moldy smell. The fix is to lift the plant, trim away any soft, slimy, or foul-smelling roots, repot into fresh mix, and ease back on standing water so the tray supplies moisture without drowning the crown.
Bringing It Together
A sundew rewards a grower who understands one thing above all: it is a bog plant that feeds itself, so the job is to recreate a sliver of nutrient-poor, mineral-free wetland and then leave the eating to the plant. Match the species to your conditions, water only with rain or distilled or RO water, pot in a peat-and-sand mix that carries no fertilizer, flood it with light, feed it the occasional tiny insect, and respect the dormancy schedule its origins demand. Do that and those glittering, insect-snaring leaves will keep putting on their slow, strange show season after season, and you will have one of the most genuinely fascinating plants it is possible to grow on a windowsill.