Sundew (Drosera) Care Information:
PLEASE NOTE: The care information we have placed here is specific to Sundews (many hobbyists call them by their scientific name, Drosera), and may not be valid for other types of carnivorous plants. For a more basic understanding of the care and maintenance of carnivorous plants, and an appreciation for how easy they are to care for, we suggest that you also read our General Carnivorous Plant Care page first.
A bit of information about Sundews and their care in general: There are scores and scores of sundew species, and even some natural hybrids; and they are found all over the world...from mountain bogs in the Alps to hillside seeps in the tropics, and everywhere in between. Because of this diversity of habitat, they are loosely broken into a number of groups. And their care can be quite different, depending on their native habitat. It should be obvious that a Drosera linearis that grows in Canada would need entirely different conditions than a Drosera intermedia that grows in the Caribbean! We will be expanding our care pages as time permits, and will be creating separate pages for each of the major groups of sundews.
The areas where sundews and most other carnivorous plants usually grow are primarily bogs and fens, where they grow in very moist, acidic, nutrient-deficient soil. Some even grow on floating mats of vegetation in the bog! Many species have been planted by humans in locations where they are not native, which can be quite a problem. We have witnessed a planting of Cape Sundews (Drosera capensis, native to Africa) that was growing in a seep with Cobra Plants in southern Oregon! Planting non-native plants in the wild is NEVER a good idea, and can even be illegal. While there are many different species, hybrids, and cultivars (named identical clones) of sundews, they all share the same general characteristics; namely leaves that have hair-like projections (most growers call them 'tentacles') on some or all of the leaf surface. These tentacles have a gland on the tip which produces a clear mucilaginous 'dew'. We love to tell visitors it's like clear snot! And it is this dew that helps them catch their prey, by causing small prey to become mired in the glue until they drown. The tentacles will then slowly move to envelop the prey, and the digestive process begins!
Regarding general sundew care, it is a good idea to do a bit of research regarding the type you are wanting to grow first. While most of the commonly available plants can be grown successfully both outdoors and indoors if provided the appropriate environment, there are some that require constant high temperatures, or a winter dormancy, or more/less water, etc. For the more common varieties, those with good outdoor growing conditions can place the pot(s) in a shallow saucer or dish. For indoor growing, a terrarium, enclosed grow rack, glass vase/bowl, or similar humidity-retaining method will help keep your plants happy and healthy.
Watering: As with all carnivorous plants, sundews require pure water of some sort, such as distilled, reverse osmosis (RO), or rain water. Bottled water and spring water from the grocery store are not recommended, as these both contain salts and minerals to make them taste better to us humans. Regardless of your growing method, keep the soil moist but not waterlogged at all times. Do not use tap water or your plant will die over the course of time. Treated tap water contains chemicals and dissolved solids which build up in the soil and will certainly affect the health of your carnivorous plant. Also, never let your plants dry out; place them, pot and all, in a tray or saucer, and add ¼ to ½ inch of water to the saucer. Don't pour the water directly onto the soil, as this can cause the soil to wash up onto the growing point of the plant and stress it. Rather, allow the water in the saucer to be absorbed by the soil before you add more water to the saucer, so that moisture can be kept in the soil but the roots have a chance to 'breathe' in between waterings. The soil around the base of the plant should always be damp to the touch, but the saucer can and should be allowed to go dry before adding more water. Remember: Do NOT let the soil dry out. You are better off using tap water if absolutely necessary, rather than letting your plants get too thirsty! A quick note if you are growing your plants directly in soil (no pots) in a terrarium: be very careful not to overwater your terrarium...it takes very little water to replace the small amount that evaporates over time!
Soil: Sundews are found in such varied habitat that it's difficult to pinpoint one generic soil mix. Most will do well in a more typical looking (dark) soil mix. We use our Standard Soil Mix, which contains Sphagnum peat, coarse-grade sand, and/or perlite. If you are in an area where you can grow sundews outdoors, this is a wonderful way to grow them, and allows them to experience natural conditions, such as dormancy (nope, not yet...more later!). However, we recommend placing a 'topping' layer of Long-fiber Sphagnum moss or coarse-grade sand on top of the soil. This helps keep the soil from being splashed up onto the growing point of the plant if there is a heavy rain event. Above all, you want a soil mix that is acidic, and it must be open enough to provide for good aeration and drainage. In our Standard Soil Mix, the Sphagnum peat provides the acidity; while the coarse-grade sand and/or perlite help to keep the soil from getting too densely packed, and provide for good soil drainage. If peat is used without a means of drainage, the roots of the plant may begin to rot. Replacement soil mixes or individual ingredients can be purchased from PetFlyTrap.com in the Supplies section. If you purchase your soil/ingredients from other sources, be certain that they do not have added chemicals, fertilizers or surfactants in them, as many name brands do. NEVER use potting soil or any nutrients of any kind in the soil: compost, fertilizers, anything that guarantees big beautiful plants. These plants get nutrients through their leaves and traps, and fertilizers in the soil may cause the roots to die off and kill your plant!
Tampering: We understand the draw, especially for younger growers, to wipe the 'slime' from the glandular hairs of your sundew onto your finger and show your friends. And yes, we have done this a few times ourselves...usually when we are doing a lecture on carnivorous plants for a school, garden club, or similar group. But overall, you should refrain from doing this, as you may affect the plant's ability to feed and it may ultimately die. Sundews work hard to produce this sticky 'glue', and may not have more when they need it. Also, if you have any kind of chemicals or other substances on your fingers, this can be transferred to the sundew. Often times, that specific leaf can die off, especially in low humidity conditions. So you can see that teasing leaves all the time can eventually cause all the leaves to die; and then you have a dead plant. Even if this doesn't happen, it can make them unable to catch prey until they can 'dew up'. How sad for the plant!
Humidity & Air Circulation: While sundews can tolerate somewhat lower humidity if they are slowly acclimated to it, they all prefer higher humidity environments, and will stop producing their sticky glue (or may even die) if they are grown without enough humidity. Higher humidity helps the glands to produce more prey-capturing mucilage, and if the humidity is too low to do this, the plant may not be able to catch anything! Lower (but not stagnant!) air circulation over the plant will aid in the maintenance of humidity. This climate is often achieved by placing the plant inside a plastic or glass dome with air holes to allow for air transfer. This can be something as simple as a 2-liter bottle or cheese ball container, or as fancy as a custom-designed terrarium! If a dome, cover, or terrarium is not available, frequent misting with pure water 9see Watering section above) may assist in increasing humidity. Keep in mind that direct outdoor sunlight while under any cover or container may result in the plant's death, due to high temperatures; these enclosures can act like a miniature microwave oven!
Food: Sundews obtain few nutrients from the soil, relying on their traps to catch insects to give them the micronutrients they need for long-term health and growth. Insects are a dietary supplement (like a vitamin pill) that help the plant to grow faster, but are not required in 'human' quantities for the health and survival of the plant; they still absorb and store energy from the sun (photosynthesize), just like other green plants. We recommend feeding your plant live or freshly killed food items (think juicy...not a dead 'husk of a bug' from your windowsill!) that are small enough for the plant to bring many tentacles into contact with it. This helps the plant digest the food faster, which can help keep the food from getting moldy. Never use fertilizer on your carnivorous plants' soil. We know of growers who will use a bit of very weak orchid fertilizer on the leaves of their plants, but we have not found this necessary here in the Houston area. We have plenty of food, and our outdoor-growing sundews often look like someone has sprinkled coarse-ground pepper on them in the springtime!
Light: Regarding lighting for sundews, keep in mind that most sundews are ground-hugging types, and grow in the partial shade of other plants...even when they're in a wide open savannah, there are grasses, pine needles, etc. that provide some shading for them. With this in mind, most sundews enjoy 12 to 15 hours of bright light, either from being outdoors if your conditions allow, or from a nearby window or supplemental lighting of some sort if they are kept indoors. If growing the plants indoors, we typically recommend bulbs in the 5500K to 6500K color range, and placed 12 to 18 inches from the plant(s), depending on the particular light system you use. The amount of light will vary with some types; Drosera schizandra, for example, prefers lower light conditions. If sundews are grown in insufficient light, the glands on the tips of the tentacles will be the same green color as the rest of the leaf. As the light increases (and depending on the variety of sundew), the red coloration intensifies. Above all, remember to slowly acclimate a sundew to any changes in condition...especially lighting. While they can take bright indirect light, it’s best to start in a lower light environment and slowly increase the amount or intensity of the light gradually to allow the plant to adjust to the environment. We have seen sundews cook in a matter of hours if they are taken directly from a dark box and placed outside in full sun!
Dormancy: As is the case with Butterworts (Pinguicula), the dormancy requirements (if any) of sundews depends on the type you have. That's easy to understand when you consider that sundews can be found from Canada to the Caribbean, and everywhere else too! Also, there are winter-growing sundews that grow from an underground tuber (tuberous sundews...imagine that!), and are dormant during the summer's hot, dry conditions in Australia. Such variation! Generally speaking, though, we typically carry the easier to grow types that require little if any special care. Just remember to do a bit of research on the normal growing conditions for the type you have. If you live in an area that is warmer or colder than their normal range, your outdoor conditions may not be adequate to give them good dormancy if they need it, and may even kill your plants!
Having said that, most sundews that we stock can be grown outdoors, and make wonderful additions to an outdoor carnivorous plant bog. PetFlyTrap.com is located just north of Houston, Texas (USDA Zone 9a), and we grow many species of sundews (filiformis, capensis, binata, and many others) outdoors year-round with no special care. They are also wonderful windowsill plants, and we have several small globe-type terrariums in our kitchen to help get rid of some of those nasty fruit flies, gnats, and other tiny flying critters.
Important Notes to remember:
1) As with all carnivorous plants, sundews will always have older leaves that are withering and dying back. This is a normal occurrence in nature; simply trim off the dead plant matter. The plants grow new leaves out from the center. You know you have a nice, healthy plant as long as this is happening.
2) Keep the soil moist at all times using the watering instructions above.
3) Generally speaking, you know your sundew plant is happy when it is producing dew drops on the ends of the tentacles. While it may take them a few days or a week to adjust to any conditions you change, we have found that humidity is the number one culprit if your plant isn't getting sticky.
4) Keep in mind that YOUR CONDITIONS WILL DIFFER GREATLY DEPENDING ON YOUR GROWING ENVIRONMENT AND WHERE YOU LIVE! Someone growing a sundew in Minnesota will need to care for their plant very differently than someone who lives in the arid deserts of Arizona!
Of course, please feel free to contact us via e-mail at [email protected] or 281-433-3290 if you have any specific questions. We're happy to help!