Sundew Recovery GuidesIs your sundew struggling? Does it look sick or have insect problems or mold / fungus problems? If so, you've come to the right place ;) This page will help you diagnose your problem and find solutions that can help your sundews recover. While this list is a bit overwhelming at a first glance, these problems can usually be easily solved if action is taken early enough. Plus, if you follow a majority of the tips on this website, these problems will rarely appear (and may not appear at all)!
If your problem isn't listed on this page, follow the instructions here to get help online.
*Note*- this guide does not cover tuberous or petiolaris sundews, since they deserve their own category.
The Table of Contents for this page is listed in the column to the right:
Dew is important for sundews because it allows them to catch insects, which in turn allows them to grow faster (and healthier) and flower. There are several factors play a role in dew (mucilage) production, including (1) light, (2) temperature, (3) humidity, and (4) air movement. Each can drastically effect the amount of mucilage produced. These variables are dependent on one another, as you will discover below---
A Basic Explanation of the 4 Main Factors Controlling Mucilage (dew) Production:
Light is possibly the single most important factor in dew production. If a sundew does not receive enough light, it will appear completely green and the tentacles will not have red coloration (normally the tentacles will turn pink or red in bright light). The dew during this time will usually only be produced in high humidity, and will be mostly water (without the sticky substance). If given more sunlight, sundews have the energy they need to produce a thicker mucilage that is more capable of holding onto insects, and will not completely evaporate in low humidity [scientific explanation will be provided soon ;)]
Compare the dew production of D. adelae leaf cuttings that were light-starved (left) vs. cuttings that were given enough light (right)
If you're growing sundews outdoors, intense light will cause higher transpiration/stress, which can end up causing your sundew to produce little or no dew during the hottest, brightest part of the day. If this is the case, you should move your sundews to a shadier location. If growing sundews under lights indoors, you can reduce transpirative stress by moving the lights further above the plants, reducing the temp, or increasing humidity.
Temperature can effect dew production because sundews can decrease or increase the amount of water they pump out through the tentacles depending on how much temperature stress there is. Higher temperatures increase transpiration (water loss), which causes the dew to evaporate more quickly. This is important for certain sundews like D. regia, South American sundews, or schizandra, which prefer cooler temperatures in order to produce the largest amounts of dew (and stay alive, as well).
Humidity is known to provide "superficial dew" that will disappear if the plant is removed from its humid environment. Humidity is important because it decreases transpiration/ water loss, allowing dew droplets to be larger. While humidity is not as important if there is no air movement, humidity can be very beneficial in higher temperatures, bright sunlight, or when there is a lot of wind. Humidity can be increased by using a small humidifier or the tray method (which is what I use).
Air movement is generally encouraged by most sundew growers, but I've found that when growing my Drosera under T-12 and T-8 fixtures with the tray method, sundews do amazingly well with stagnant air conditions (wand ~45% humidity). Air movement is usually advised in humid conditions (like a terrarium) since it can encourage fungus or insects to thrive. Airflow is also needed when temperatures are higher (90-100 degrees F), because it increases the amount of evaporative cooling that takes place. However, air movement also leads to higher transpiration rates, which decreases the amount of dew unless higher humidity is provided. The room I grow my sundews in doesn't even have a vent in it, so there is never any air movement. Even though temperatures are nomally 85-90 degrees F, my South American and other common sundews do suprisingly well and have tons of dew during the summer months because there is so little air movement, and the humidity is high enough from using the tray method.
Summary: As you can see, each variable can influence the rate of transpiration and overall "stress" put on the plant. You can modify the conditions of light, temperature, humidity and airflow in order to encourage the smallest amount of transpiration/ stress, which in turn increases the size of mucilage produced by your sundews.
There are many potential reasons why the leaves on your sundew may become deformed:
1. It's the plant's fault (1 or 2 leaves may look weird, but the plant is perfectly healthy)
2. Environmental problems (i.e. it's too hot)
3. Insect damage (e.g. aphids).
You should only start worrying when 3 or more leaves in a row have become deformed or if the plant looks like it's declining. Submit a picture of your sundew to a forum, such as terraforums.com or cpukforum.com and the community there can help diagnose your problem. Other times, leaf deformation can be caused by humic acids, found in peat moss (explained in the paragraph below).
"Natural" Leaf Deformation
Sometimes your sundew may "mess up" when making new leaves. These natural mistakes can occur when the "ingredients" used to make new leaves are present in abnormal amounts. This occurs randomly and depends on specific combinations of temperature, humidity, and the other variables described earlier. So in this case, there's nothing to worry about. Your sundew should make normal leaves soon.
Above: Only half of the (left) leaf on this Drosera binata plantlet decided to unfurl...
Sundew Leaf Deformation from Insect Damage
If you can see small insects positioned on the crown or petioles of your sundew OR if you see insects in the soil that might be eating younger roots (ie fungus gnat larvae)
Refer to this youtube video by Sarracenia Northwest and this page about Neem Oil for some options of getting rid of pests.
Solutions: How to Prevent Insects from Harming Your Sundews:
1. Let your pots dry out slightly in-between waterings. This can prevent insects from thriving in the soil.
2. Provide your sundews with more light. Aphids are often associated with light-starved sundews
3. Increase air circulation around your plants. Insects are frequently associated with stagant conditions (although if you follow my lighting, soil, and watering instructions, this should usually not be a problem).
Sundew Leaf Deformation from Black "Humic Acids"
The leaves on my sundew are small and deformed, and there is a black substance at the crown of the plant. What do I do?
"The darkening of the growth point," as shown by the photograph [below], "is caused by humic acids, and perhaps other solubles, wicking up and depositing themselves, first on the hairs and stipules of the leaf primordia, eventually covering the entire surface of the growth point and leaf primordia. New leaves tend to be deformed and are devoid of dew."
Refer to the following 5 solutions, below the picture:
This problem can still occur even when your sundews would otherwise be completely happy, so don't be discouraged!
Solutions for leaf deformation caused by humic acid buildup:
1. This substance can be wiped off by rubbing the affected area with a moist cloth (warm water works well). This alleviates the problem in the short-term
2. Top-watering the soil over a long enough period of time will eventually flush out the majority of the humic acids from the pot. Rinsing your peat can help this immensely. Even some high quality peat brands can cause this problem.
3. Using a mix with a lower ratio of peat moss can improve conditions, since it the main source for the most offending compounds.High quality dead or living long-fibered sphagnum is usually the best alternative.
4. If you keep the soil moisture at a lower level, this will prevent the wicking effect and will reduce humic acid buildup.
5. This problem "is also affected by temperature, ambient humidity, air movement, etc." Try making adjustments to these options if the soil modifications don't eventually solve the problem.
Click here for a reference about the above info
What does "Acclimating" or "Hardening" a Sundew Mean?
Acclimation is the gradual adjustment of a plant to new conditions.
The Webster Definition of acclimate is: " to adapt to a new temperature, altitude, climate, environment, or situation" [http://www.merriam-webster.com/dictionary/acclimate]
Acclimating a sundew to lower humidity
This means that if you buy a sundew from Lowes (either a D. capensis or D. adelae most of the time), in order to take the sundew out of the cube, you will have to gradually expose the sundew to lower humidity by slowly sliding the lid off of the cube until it is finally removed after a week to 2 weeks. The dew droplets will likely be smaller than when the sundew was grown exclusively inside of the cube (due to the reasons described above)
Above Left- Drosera adelae (purchased from Lowes) fully dewed inside of its cube
Above Right- A different D. adelae plant, after an acclimation period of 2 weeks (notice the smaller dew droplets.
Acclimating a Sundew to Brighter Light [To Avoid leaves burning (browning) at tips.
Many new sundew growers report that their sundews' leaves burn up or turn brown when the bring them outside for the first time. Considering enough water was provided, this generally means that the light intensity (and heat, as well) was too much for the sundew to handle. Also, the leaves may lose all their dew and the leaves will appear "sunburnt" (an unhealthy pink/red coloration).
This is what I normally advise:
1. Grow the plant in a shady location for a week or two (to ensure that the plant is able to adjust to the conditions outdoors first)
2. Move the sundew to a partly sunny location for several weeks until it has colored up and appears to be established.
3. Be very observant of how the sundew adjusts- if the plant looked fine in the shady locaiton, but appears to be stressed in part sun, consider moving it back and letting the sundew acclimate there for a longer period of time. If the sundew is stressed the second time when bringing it back to a partly sunny location, consider permanently growing it in the shade. (The same applies for acclimating a plant from part sun to full sun).
You may notice that sundews grown in brighter light no longer need as much humidity to produce large dew droplets (but this is not always the case, and varies from time to time).
Below- compare the same Drosera adelae plant (before and after acclimation to a brighter location)
Acclimating a Sundew to Warmer temperatures
Acclimation to warmer temperatures follows the same basic technique as the other forms of acclimation. If you want to move your sundews outdoors in the heat (in Singapore, for example), but you've been growing them in air conditioning for a long time before that, then do the following:
1. Move the sundews into the location you plan to grow them in (considering light acclimation as well) and leave them there for a half hour. If they look ok, then leave them for an hour.
2. Take them back indoors and let them recover (may not be necessary if conditions are favorable outdoors)
3. The next day, place them outside for 2 hours (or however long before they begin to show signs of stress).
4. Repeat step 2.
5. Gradually increase the time you leave them outdoors until they can be left outside all day long without showing any serious signs of stress. The sundews will inevitably be more stressed outdoors than in air conditining indoors, but the stress I'm describing is more severe- such as complete loss of dew coupled with minor wilting even when there is plenty of water in the pot or tray.
Root Rot: The leaves on my sundew are wilting and the tentacles have all curled up! [OR Leaf tips are turning Brown]
Root rot may arise from several reasons: [If you have already ruled out insects, too much light, or drying out as being the issues]
1. The water level is kept too high (or the pot is too short)
2. The tray is never allowed to dry out
3. The soil mixture does not drain well enough
4. The temperatures may have cooled, making the plant more susceptible
5. The light intensity may have decreased, making the sundew more susceptible.
Symptoms of Root Rot: The tentacles of the sundew will completely curl up and lose their dew (see pictures below). Also, in the case of Drosera graomogolensis, the sundew may suddenly decline turn brown after losing its dew.
Picture to the left: Drosera nitidula x pulchella is suffering from root rot, right next to healthy sundews of the same species, in the same pot.
The soil mixture was 2:2:1 peat:perlite:sand, which did not drain well enough for this sensitive species. Additionally, the temperatures started decreasing and the photoperiod had decreased a bit, as well. This problem was solved by increasing the photoperiod of the fluorescent fixtures to 16 hours instead of 11-12 (close to gemmae-producing range) and letting the soil dry out.
To the left: Drosera admirabilis is also another another species with quite sensitive roots. Notice that it is recovering after all its tentacles lost their dew and completely curled up. This problem was solved by transplanting it into a tall pot (6+ inches) and using 1:1 peat:sand, and letting the tray dry out occasionally. There will still occasionally be issues, but they won't be as dramatic as the above situation.
Solutions for Root Rot:
1.) Use a taller pot- this will make the moisture distribution around the roots less variable, and will elevate the roots further away form the water table in the tray.
2.) Use a well-draining soil mixture. Sand seems to dramatically improve this problem (in my conditions) in comparison, in replacement of perlite. Perlite works much better when there is a lot of air circulation.
3.) Let the tray dry out occasionally before filling it up again. This reduces pest growth, such as fungal pathogens and pathogenic insects. Be careful that the soil doesn't completely dry out when you do this, or your plants may dry up!
4.) Increase the photoperiod you're using (if you use supplemental light fixtures)
5.) Increase air circulation
Also, refer to the soil issues directly below, which could also be causing similar problems:
Anaerobic Soil or Compaction: My sundew is starting to decline even though it's been growing well for a year or more!?!
The problem: If you have already ruled out plant pests as being the issue, and you haven't changed your sundew growing conditions recently, your problem is most likely due to a problem with the soil. Over time, the peat and sand mix can compact, reducing the oxygen that the roots are able to receive. [Scientific Explanation: This causes the resperation in the roots to proceed predominately through the anaerobic pathway of energy production (leading to a chronic buildup of ethanol, which is toxic in large enough amounts). Although sundews can handle anoxic conditions in the soil much better than the majority of "normal" plants, they are still susceptible once ethanol levels are high enough. As a result, the sundew will be less able to absorb minerals.] This is especially a problem if you are growing your sundews indoors and aren't feeding them or are keeping them in an airtight container or small terrarium with little air movement!
A diagnosis- Symptoms of Anaerobic Soil or Compaction:
Diagnosis #1. Compare the roots of your plant to normal, healthy roots.
Normally, the roots of [many common subtropical] sundews will be fairly thick, with white apical meristem tissue towards the tip:The picture to the left shows a healthy root of Drosera adelae.
In unhealthy roots (highly anaerobic), there will be very little "white" cooration visible towards the tip of the root. Also, you may notice the roots will be much more thin and fragile (pictures to come...)
Symptom #2. The leaves may start looking sickly or yellow and begin to die. Leaves may turn brown, as well, and all the dew may be lost.
Symptom #3. The soil may smell very potent and disgusting. Ideally, there should be a very minimal scent to the soil and it shouldn't smell like sulfur.
The solution for Soil Compaction or Anaerobic Soil:
1. Re-pot your sundew in fresh soil, according to this guide (in the soil compaction paragraph) and observe how your plant adjusts over the next month.
2. Top-water your sundew regularly: As the water flows through the pot, oxygen is pulled through the pores of the soil. This can improve issues, without needing to re-pot.
3. Feed your sundews regularly if grown indoors: Regular feeding will greatly prolong the onset of any problems even in very compact soils. This is because the sundew won't need to rely as much on its roots to obtain the nutrients and minerals it needs to stay alive.
Heat Stress: My sundew lost all its dew and the leaves are turning yellow or sickly pink and the leaf tips are browning!!
The problem: Certain sundews can not handle warm temperatures as well as others. This is especially a problem for younger sundews. Eventually, after a few years of developing a strong root system, these issues will be minimal.
A few examples:
Drosera slackii heat stress progression (picture descriptions below)-
A. First signs of heat stress in mid-spring ~85 degrees F
B. In the middle of summer ~90 degrees F
C. In the fall, with cooler temperatures ~65-80 degrees F max
Drosera aliciae heat stress- Some forms grow well in the heat, and others decline and resemble the symptoms of Drosera slackii, shown above.
Drosera oblanceolata heat stress examples are shown at this link. The leaves will change their shape and will lose most of their dew.
Drosera regia heat stress- Above a range of ~85 degrees F, the plant will turn black and completely die back to the roots.
Solutions for Sundew Heat Stress:
1. Use cooler temperatures: If you are able to provide your heat-sensitive sundews with cooler tempreatures (in a basement, for example), then these problems will not occur.
2. Provide higher humidity: Providing higher humidity has the potential to reduce transpirative stresses brought on by warmer tempteratures.
3. Use living sphagnum moss: Living sphagnum has great cooling properties on the root system of carnivorous plants due to its "wicking" effects. While it may not cure the issue, it usually helps.
Can't Find the answer to your problem here? Get help from the Carnivorous Plant Forums!
There are many experienced growers on the web who are happy to answer your questions at the following (main) sites (and see below for what info to include with your post):
***Important information to include when you make a post about your sundew problems:
- Drosera (sundew) species name: (e.g. "Drosera capensis")
- A picture of your plant (also helps if you don't know the sundew's identification)
- How long the plant has been under your care
- Your location (city and state, for example)
- A description of your growing conditions (as much info as possible):
It is very hard to help fix your sundews' problems without this info!
- Tray method/Terrarium
- What light setup do you use (by the window or under fluorescent fixtures)
- Pot size & height
- Soil mixture composition
- Water level in your tray (or describe your watering regimen)
- Temperature where your plants are growing
- Relative Humidity
Happy growing, and I hope your sundews have a speedy recovery! :D
Additional Questions or Suggestions?
Contact me at: sundewman(at)yahoo.com