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With their unique colors and even more distinct feeding habits, it is no surprise that sundews have become one of the most popular carnivorous plants today. If you want to try growing one of these, it is important to know how much light they need. Are you providing too much or too little? Can you use indoor grow lights or not? Those are the questions that will be answered here.
Sundews need 8 to 12 hours of light per day, sunlight or grow lights are fine. A combination of direct and partial light is best. Do not place sundews under full shade, but some shade is necessary if the temperature exceeds 100 F.
Do Sundews Need Direct Sunlight?
Sundews or drosera benefit from a combination of direct and indirect sunlight. Do not expose the plant directly to the sun for prolonged periods because the heat could damage its leaves. Some drosera species like D. capensis can handle direct sun, but others such as D. spiralis are more sensitive and need partial shading.
Sundews can handle a wide range of temperatures, but the most ideal is 45-85 F (8-29 C). Direct sunlight is good for drosera but if the temperature is too high this could end up drying or burning the leaves.
Depending on the sundew species it may be able to handle direct sunlight better than others. Some types can get acclimatized to the sun and still grow. But others are not as adaptable and require cover during hot days.
If the temperature is between 48-90 F, your sundews will be fine. Most likely it will get direct sunlight for a few hours and then as the afternoon draws near, light intensity goes down.
If you live in a moderate climate, you do not have to worry if your sundew is getting enough sun. A few hours of direct sunlight at noon and partial light for the rest of the day. As long as the plant gets proper soil and nourishment it will be fine.
Aside from sunlight, sundews also need water. Rainwater, distilled water or reverse osmosis to promote growth and health. Tap water has mineral deposits that might harm the plant, so you should avoid that. We particularly prefer Resway Distilled Water because it is safe for carnivorous plants.
If you are not sure if your sundews are getting too much sun or not, check its leaves. If it feels dry or has a crispy texture to it, that means the heat is affecting the plant. If you do not move the plant under shade, those leaves could blacken and burn, similar to what happens with Venus flytraps.
Why Do Sundews Need Sunlight?
Since sundews feed on insects, but that does not lessen their need for sunlight. Contrary to popular belief, sundews require sunlight to survive much more than feeding on insects.
Sunlight provides sundews with the energy they need to live. Insects supply sundews with extra strength to do photosynthesis and produce more energy.
Sundews do not consume insects as food. They are properly termed nutrients which make the plant stronger, similar to what vitamins and supplements do for humans. Sundew food – or more accurately energy – comes from glucose, which they create through photosynthesis.
Sundews require sunlight for photosynthesis. Without it they cannot produce glucose which is essential for their survival. Carnivorous plants can survive for long periods without bugs, but not light.
Some sundews need more sunlight than others. The drosera adelae will survive with just a few hours of sunlight. Other variants require a minimum of 12 hours, with 15 even better. If natural light is limited, you can augment it with AeroGarden Harvest Elite Lights which are efficient for plants.
This does not mean sundews will die if there is only a few hours of sunlight available. In this case you can always use artificial lights to simulate the sun.
No matter what sundew variant you buy, it is a good idea to check how many hours of sunlight it requires. This will save you a lot of trouble later on. As a general rule, these plants need at least 6 hours of sunlight.
Depending on where you live this might not be possible, so have sunlight alternatives available. During its growth season, sundews will need as much light as possible. Unless it is burning hot outdoors, just leave your plant there and let it soak in the sun.
Of course sunlight is not the only thing sundews require. You also have to use the right soil mix. Once the soil is ready never let it get completely dry as that will harm the plant.
Can I Use Grow Lights on Sundews?
It the importance of sunlight for sundews is clear. But what if there just is not enough light available? Does it mean you cannot grow these plants? Not at al, as artificial lights are available.
You can use indoor lighting if sunlight is not available. Leave grow lights on several hours a day for the best results Position the light 12 inches above the plant for the best results. You may use higher powered lights, but 40 watts is usually enough.
Indoor grow lights have improved a lot and benefit all kinds of plants including sundews. In cases where sunlight is limited to just a few hours day, indoor grow lights are a fine alternative.
The best case scenario is your sundews will get full natural sunlight all day. The next best is the plant gets a few hours of sunlight each day and you supplement it with indoor lights.
If there is only a little sunlight available, use the grow light. If the sundew is in its growing phase, point the light directly. But if you are not sure, leave the light directly on the plant.
After a couple of weeks, check if the leaves dried out or turned red. Provided the answer is yes, it means the lighting was too harsh. Move the light so it is indirectly shining on the sundew.
Light is only one part of the equation. The temperature, humidity and environment are crucial as well. If it is gets very cold in your area, you might need to move the plant indoors to provide it warmth.
Lighting Tips For Sundew Plants
- Whether you opt for direct or indirect sunlight, never place sundews under full shade. This is going to be fatal to the plant. Remember that without sunlight, sundews will not be able to produce glucose, their source of energy.
- If you want to keep sundews indoors, place it on a window sill with plenty of sunlight. As long as the container is properly placed, the plant will get the sunlight it requires. And if the sun is too hot, you can just move the pot to another location.
- Sunlight can only do so much, as the right soil is required too. Sundews prefer a 1:1 mix of perlite and peat moss, the same as Venus flytraps. And keep the soil moist so the roots do not succumb to infection and weaken.
- Keep an eye on its traps if sundews are indoors. If the sundews are no longer able to catch bugs the way it used to, it is a sign the plant is not getting enough sunlight. Relocate the plant, outside if necessary, so it can get more sun.
- A mixture of direct and indirect sunlight are great for sundews. If the plant is indoors, it will probably only get indirect light. in that case you have to double its exposure. Use as many grow lights as possible if necessary.
- Colors are a good indicator of sundews health. Vivid colors are good signs, while dull, pale colors mean lack of light and nourishment.
- Fluorescent lights are better than incandescent lights for sundews. Incandescent lighting can get very hot and burn the leaves. Fluorescent lights on the other hand, might actually help speed up growth of your sundew plant.
- A 5500-6500k color spectrum is the best for fluorescent lights. Again, watch out for the colors to determine if it is responding well to the lighting.
Sundews need sunlight like other plants, but you also have to strike the right balance. Too little light is not good for sundews obviously, but too much is not healthy either. By following the steps in this guide you can rest easy knowing your sundews are receiving the right amount of sunlight.
My fascination with carnivorous plants began many, many years ago with Venus Fly Traps. Now I am more than happy to impart what I know with other enthusiasts and those who are curious about meat eating plants.