Sundews, known scientifically as Drosera, are incredibly interesting carnivorous plants. They lure, capture, and digest insects using the “dew” that is on the surfaces of their leaves. Since the dew of a sundew is vital for its survival, it can be frustrating when your plant is not producing the dew it needs. Luckily, there are some simple fixes to get your sundew creating dew again in no time.
So, what are the top 3 reasons that there is no dew on your sundew?
- Leaf Deformities
- Environmental Problems
- Damage from Pests
Each of these causes has specific fixes that can help nurse your sundew back to good health and allow it to produce dew again.
The Top 3 Reasons There’s No Dew on Your Sundew
Sundews do not actually produce what we know to be dew. They produce a sticky substance called mucilage from mucilaginous glands that are on their leaves. It resembles the dew that you find on plants in the early mornings. Because this mucilage is what captures its prey, it is important that the glands produce the mucilage that the sundew needs.
There are three common reasons that mucilage production is disrupted: leaf deformities, environmental problems, and damage from pests.
Reason #1: Leaf Deformities
Leaf deformities are sometimes the result of natural causes. Other outside causes of leaf deformities are insects, black “humic acids,” and lack of plant acclimation.
There are times that a sundew’s leaves simply do not grow properly. If you’ve done everything right when it comes to taking care of your sundew and you’ve checked all the underlying causes of poor sundew health, then your plant may simply be having a few issues growing its leaves. Most often, natural leaf deformities fix themselves.
If insects are the problem with your leaves, you may be able to see them clearly if they are on the plant itself. However, sometimes, the insects are inside the soil eating younger roots. If this is the case, you will normally see them crawling around in the soil.
Three solutions for insect damage affecting the formation of your sundew’s leaves are:
- Water your plants a bit less to allow them to dry out between waterings. This will help prevent insects from being able to thrive in the moist soil.
- Give your sundews more light. Some insects, like aphids, are associated with sundews that are starved for light.
- Make sure there is proper air circulation around your plants. Insects are often found in stagnant conditions.
Black “Humic Acids”
Humic acids can deposit themselves onto the leaves of the plant, and this results in a darkening of the leaves. First, you’ll notice the hairs on the leaves darkening, but eventually, the entire plant can be covered in humic acids. Once humic acids reach the growth points of the leaves, new leaves that grow are deformed and do not function properly.
Five solutions for black “humic acids” overtaking your sundew include:
- If the humic acid is only in a few places, you can wipe it off with a cloth that is moistened with warm water. Be aware that this is a short term solution.
- You can start top-watering your soil, which can flush the humic acids from the plant pot. You can also rinse your peat often.
- Change to a mix that has a low ratio of peat moss because peat moss is usually a main source of black humic acids. You can use high-quality dead or living long-fibered sphagnum as an alternative.
- You can try keeping the moisture of your soil at a lower level to reduce the buildup of humic acids. An easy way to check this is using a moisture meter.
- Adjust the temperature, humidity, air movement, or other adjustable conditions to see if it helps.
Lack of Plant Acclimation
Acclimating your sundew is important. Acclimation is the process of helping your plant adapt to new temperatures, altitudes, climates, environments, or situations. Three common sundew acclimations are adjusting the plant to a lower humidity, getting your sundew used to brighter light, and preparing your plant to live in warmer temperatures.
Plant acclimation always involves patience. If you expose your sundew to conditions that it isn’t used to without preparing it, it may not survive. Make sure to follow all the steps for your plant’s specific acclimation in order to ensure that your sundew thrives. The steps will vary depending on the kind of sundew you have purchased and where you live.
Reason #2: Environmental Problems
Environmental problems are another reason that can result in no dew forming on your sundew. There are four main environmental factors that control mucilage production, and there are three common environmental issues that can arise that can result in low dew production.
The four main environmental factors that control mucilage production are light, temperature, humidity, and air movement.
- Light is the most important environmental factor for mucilage production. If your sundew doesn’t get enough light, it will stay completely green, and there will be no red coloration on the tentacles. When there is not enough light for your sundew, the dew that is produced will be mostly water, only produced in high humidity, and not very sticky at all, so the sundew cannot catch prey.
In contrast, if your sundew is getting too much light, the plant will have a higher transpiration and will not be able to produce dew during the hottest or brightest part of the day.
- Temperature is another face that can affect dew production. The temperature will affect how much water your plant can pump out through its tentacles. High temperatures cause water loss and can make the dew evaporate really fast.
- Humidity is an important factor to manage because proper humidity will lessen the water loss in the plant and the dew droplets will be larger. Humidity is necessary in higher temperatures, bright sun, and lots of wind. You can increase humidity with a humidifier if needed.
- Air movement is another environmental factor to control when dealing with mucilage production. It is especially important to have proper air movement in humid conditions in order to discourage the growth of fungus or the introduction of insects to your plant. Air movement is needed for high temperatures because it helps to increase evaporative cooling.
Three common environmental issues that can arise that affect dew production are root rot, soil issues, and heat stress.
Root rot becomes noticeable when the leaves, or tentacles, of the sundew completely curl up and lose their dew. In some cases, the sundew will also turn brown.
Causes of root rot include:
- A water level that is too high
- The pot’s tray is never able to dry out
- The soil does not drain well enough
- The temperature may have cooled too much
- Light intensity may not be high enough
Solutions for root rot can be:
- Use a taller pot to allow for better moisture distribution in the soil and more elevation of the roots, so they aren’t touching the tray.
- Use a soil mixture that drains well. You can replace perlite with sand, in some cases, to help the soil drain. If there is a lot of air circulation, though, then perlite usually works better.
- Allow your tray to dry out completely sometimes before you fill it back up. This helps to decrease pest growth. Make sure you don’t let the soil completely dry up, though. This could make your plant dry up.
- Increase the photoperiod you are using if you use any light fixtures to increase your plant’s lighting.
- Increase the air circulation of your plant.
Both anaerobic soil and soil compaction can result in unfavorable conditions for sundew growth and health. Anaerobic soil has a high moisture content; it is typically found in wetlands and floodplains and can be found in our gardens and potted flowers and plants when the water level is kept too high.
Soil compaction happens when the particles in soil are pressed firmly together. When this happens, the soil becomes denser and doesn’t allow for proper water drainage. Soil compaction in a potted plant is especially frustrating because pots are designed to drain, and poor soil drainage is not suitable for proper plant growth – especially when it comes to sundews.
Symptoms of anaerobic soil or soil compaction can be:
- The roots of your plant are unhealthy. Unhealthy roots in these cases will have very little white coloring visible toward the tip of the root, and the roots will generally be much thinner and more fragile than healthy roots.
- The leaves on your plant will suffer. They will start looking sickly, turn yellow or brown, begin to die, and can even stop producing their dew.
- The soil will smell bad. Healthy, aerated soil will not have a smell or will have a very minimal smell. Anaerobic and compacted soil can smell very strongly or putrid.
Fixes for anaerobic soil and soil compaction include:
- The best solution for a plant that is suffering from poor soil is to re-pot the plant in fresh soil. Once you’ve re-potted the plant, you can observe it for a few weeks to see if it gets better or if there is another underlying issue.
- Start to top-water your sundew. Top-watering makes water flow directly down into the pot and pulls oxygen through the soil. This could fix the issue without needing to re-pot.
- If your sundews are located indoors, feed them regularly. If they are allowed to eat insects often, they will not need to rely on their roots as much. This can prevent them from having to rely solely on their roots for survival.
Heat stress can exhibit itself in a number of ways depending on the particular type of sundew you are growing. Some ways that too much heat can affect your plant are the following: a change in leaf shape or color, lessened dew production, and discoloration that can reveal itself as brown, black, or a sunburned red color.
Some solutions for dealing with heat stress for your sundew are:
- Provide cooler temperatures for your sundew. Moving outside plants inside and moving inside plants into cooler parts of your home, like a basement, can help.
- Provide more humidity. Giving more humidity to your plant will help it transpire less when warmer temperatures come. It won’t lose as much water, so it can stay healthy.
- Try using living sphagnum moss. Living sphagnum moss has awesome cooling effects on the root system of carnivorous plants.
To prepare for heat stress on your plant, it is important to know when it begins in the seasons. Heat stress will usually manifest itself in mid-spring around 85 degrees Fahrenheit, in mid-summer around 90 degrees Fahrenheit, and in fall between 65 and 80 degrees Fahrenheit.
Reason #3: Damage from Pests
Even though sundews eat insects, they can still fall victim to insects as pests.
Aphids are also called greenflies. They normally do their damage to most plants in spring, but in small plants like the sundew, they can winter in the plant and its soil and do damage before the leaves even grow in the spring. Aphids are very small, so you may not be able to see them. However, if you notice little white specks of shed skin and a sickly plant, you probably have aphids.
The Fix: To get rid of aphids, use a systemic insecticide.
Mealy Bugs are rather common insects that are fuzzy and white and feed on the juices of plants. They are bearers of disease and infection. They often go unnoticed because they hide away from the light.
The Fix: You can use a Q-tip dipped in alcohol or a systemic insecticide to get rid of mealy worms. You can remove them with your fingers as you see them, as well.
Scales are unique looking bugs that look like fish scales stuck onto the stems of a plant. They most often occur in colonies and can spread quickly when untreated. Adult scales are usually attached to the underside of the stems permanently, out of sight. Young scales will travel a bit on the stems. Their droppings are very sugary and cause dark mold to grow.
The Fix: To remove scales, it is best to use your finger because even a systemic insecticide can take multiple treatments to get rid of them all. Remove them as you see them.
Which Sundews are Easiest to Care For?
Because there are close to 200 different species of the Drosera, or sundew, plant, it is no surprise that some species are easier to care for than others. Why not chose one that is easier to care for to up your chances of your sundew having dew?
One of the biggest indications of whether or not you will successfully be able to care for a sundew is the climate in which the species typically lives.
The easiest species to care for is cape sundews, scientifically named Drosera capensis.
- Cape sundews are so incredibly easy to grow that they are often considered a weed in many sundew collections.
- In New Zealand, this species of sundew is considered invasive.
- They are called Cape sundews because they are native to the Cape of Good Hope in South Africa, so they are tropical plants. However, they have been successfully grown next to temperate plants like Venus Flytraps and American pitcher plants year round often.
- Cape sundews will not survive very cold winters outside, so remember to bring them inside during winter.
- They do not need a dormancy period, so you can keep them on a sunny windowsill inside your home all year.
- There are a few different forms of Cape sundews.
- typical Cape sundew – green stalks and red dew drops
- “all-red” Cape sundew – entire plant turns red in bright sunlight
- “albino” Cape sundew – plant has green with white dew drops and flowers
- Available in wide-leaf and narrow-leaf formations
Cape sundews are, by far, the best carnivorous plant for a beginner. There are also other tropical and temperate sundews that you can choose from that are easy to care for.
Other species of sundews that are great for beginners include:
- Tropical – spoonleaf sundew – Drosera spatulata
- Tropical – fork-leafed sundew – Drosera binata
- Tropical – lance-leafed sundew – Drosera adelae
- Temperate – thread-leafed sundew – Drosera filiformia
- Temperate – oblong-leafed sundew – Drosera intermedia
- Temperate – round-leafed sundew – Drosera rotundifolia
One thing to watch out for when you successfully grow your sundews is that they can begin to multiply at rapid rates, which can lead to carnivorous plants popping up around your yard or your terrarium without you planting them. The far-reaching root systems and healthy seed production make these plants amazing proliferators.
Carnivorous plants are very interesting plants to keep. Sundews have been classified as carnivorous since 1875 – when Charles Darwin himself classified them as such in his book Insectivorous Plants. In fact, Darwin stated that he cared more about sundews “than the origin of all species of life on earth” in a letter to his friend Asa Gray, who was a botanist.
Darwin “described the fascinating insectivores as being more sensitive to touch and taste than the animal species he had studied and mused that they were really animals in disguise.” Sundews are incredible, and they have captured the interests of scientists and plant lovers alike for hundreds of years.