Drosera adelae-The Lance-Leaf Sundew

Drosera adelae is a great beginner's sundew, but it can be a bit picky for some growers. It was my first carnivorous plant, and I was lucky enough to have success with it. A  Drosera adelae recovery guide is provided at the bottom of this page for growers who are having problems growing this species. Advice for growing D. adelae outdoors, and on a windowsill is also provided at the bottom of this page.

Drosera adelae is a member of the "3 Sisters of Queensland," a group of closely-related sundews endemic to Rockingham Bay, Hinchinbrook Island in Queensland's tropical rainforests (Lowrie 132). Drosera adelae is able to grow well in brighter locations and lower humidity in comparison with the more difficult D. schizandra (another member of the 3 Sisters of Queensland). I recommend Drosera adelae to most beginners, because it is readily available at Lowes and other stores for a reasonable price---and if you can make this sundew happy, it provides a good indication that other sundews, such as D. capensis or D. spatulata, should do well in your conditions. D. adelae is commonly observed to grow back from its roots if a plant dies or declines .

Habitat: In nature, Drosera adelae can be found growing in "mountain areas among rocks in sandy banks along creeks in rainforest" (Lowrie 132). Check this picture out to see Drosera adelae growing in the wild on the side of a vertical cliff. Flowing water seems to be beneficial to growth.

Media: 100% Long-Fibered Sphagnum (LFS), living sphagnum, a peat: sand mixture (perlite also works well for several growers), or a mix of LFS with some sand. Drosera adelae is generally not picky if all the other factors are accounted for (such as temperature and humidity). However, others have reported that they can only get this species to grow in dead or living long-fibered sphagnum. The plant pictured at top left is growing in 100% LFS.

Media moisture: very moist to slightly moist. Usually very adaptable if all other conditions are favorable. In lower light levels, or if unhealthy, D. adelae may have a more of a tendency to rot if the water level is kept higher. 

Humidity: thrives for me if if given higher humidity during warmer temperatures. Much less humidity (<25%) is needed in cooler conditions (i.e. below 70 F). I especially recommend higher humidity levels if you have recently transplanted your D. adelae, since this plant (and even D. capensis) can be sensitive to heat and low humidity for a certain period, especially if the roots have been disturbed or broken in the process. While growers tend to have very differing opinions about humidity, it mainly depends on the the conditions that the plants are growing in (ie lighting, temperature, etc), which can vary considerably.  I always recommend experimenting until you find what works best in your condiitons.

Feeding: Drosera adelae grows best (and largest) when fed at least once a month or more frequently. If growing in a high humidity environment (ie in a terrarium or sealed container), try not to overfeed the leaves or mold may develop. A "paste" of freeze-dried bloodworms (mixed with some water) has been reported to not produce mold growth, even in high humidity environments. Visit the feeding page for more info.

Trap speed: medium. D. adelae generally has very little leaf movement unless a very large piece of food is caught by or fed to this sundew. However, the tentacles are quite active and will begin to visibly curl around prey in within a half hour.

   

Pot height: The taller the pot, the better, when it comes to growing the largest D. adelae. Larger than 4 or 5 inches tall would be a good start... Check out this picture of the root system of a small plant of D. adelae I unpotted (roots around 10-inches long. If you don't care about the size of your plant, then any pot size 2 inches or larger will be adequate, provided an appropriate water level is maintained. Avoid using clear pots, since the roots frequently develop new plantlets whenever they are exposed to light--- this wastes a lot of energy from the mother plant, and will consequently reduce its potential size. Also note that Drosera adelae tends to send out more horizontal roots if it's grown in a shallower pot. In this case, it may devote more energy towards propagating itself than to increasing the size of its leaves. Choose a pot that best suits your preferences. 

Plant Dimensions:
Leaves- "Lamina narrowly lanceolate, 10-25 cm long...petiole short to almost none" (Lowrie 132). So far, the largest plant I've seen in cultivation had 6-inch-long leaves. The leaves of my D. adelae have remained 1-2 inches long when not fed regularly (fancy way of saying "ignored" ;)) and given high light intensity. See light's infulence on leaf size below.
Structure/Height- According to Allen Lowrie, plants in the wild can reach a height of 25 cm (~10 inches). "The leaves in the early stages of growth erect and circinate, unfurling to a semi-erect position then slowly becoming horizontal as they age" (Lowrie 132). Drosera adelae generally tends to form a stem over time. In "perfect" conditions, this stem growth will be extremely slow. Stem elongation will increase if given lower light intensity, and will decrease if more light is provided. Once the stem reaches too high above the media surface, the plant will start to decline- especially in warmer temperatures. I've had success combatting this by burying the excess stem back into the media, or by using living sphagnum as a top-dressing, which grows at about the same rate as the plant. Living sphagnum is great at providing moisture to the stem of D. adelae so that the stem can continue to root and sufficient water for continued growth can be obtained.

Outdoor Growing: To be safe, when acclimating D. adelae outdoors, start by growing it in a very shady location. If it is doing well, you can leave it in that location, or gradually move it into an area that receives more light. If not given time to adjust (acclimate), the plant will often become fried in the sun. For more information about growing sundews outdoors, click here.

Dormancy requirements: Drosera adelae does not need dormancy if given tropical or subtropical conditions year-round, but grows as a perennial in nature if the temperatures drop below freezing for a given time (Lowrie 132).

Light intensity & Photoperiod:  D. adelae does quite well in stronger lighting. It will turn bright red in bright conditions. If you want to grow Drosera adelae safely outdoors, I'd recommend partial shade. The photoperiod does not seem to effect dormancy. Lower light intensity tends to encourage increased leaf elongation, but be sure that the tentacles still retain a red or pink coloration, or this is a sign your plant needs more light. The picture below to the left provides an example of a healthy plant grown in lower light intensity. Also note the increased stem elongation on this plant as well.

 

Above left: D. adelae with 3-inch leaves grown with lower light intensity (Photo by Devon Blomquist). 
Above right: D. adelae root cuttings (with Byblis liniflora) growing in 80-85 F temps inside a sealed container. The elevated humidity allowed them to thrive in these warmer conditions.

Temperature: As a tropical sundew, D. adelae does well in warmer temperatures as long as there is sufficient humidity. Also, make sure  the soil is never allowed to dry out during times of heat stress. My plants (in high humidity) have tolerated temps of up to 90 degrees F just fine, but plants grown indoors next to a dehumidifier at warmer temperatures didn't do very well. These plants only came back to life when temperatures cooled. In my conditions, the Queensland sundews prefer cooler environments if they are not given additional humidity. Drosera adelae seems to thrive in temps around 70 degrees F in humidity levels around 35% or less. Since D. adelae does not require a dormant period, keep the temperature above 45-50 degrees Fahrenheit encourage healthy growth.

Flowers and Seeds:  "Petals red, reddish orange or cream" (Lowrie 132). The flower forms a star. In nature, Drosera adelae flowers from June through November. The plants apparently DO produce viable seed if manually self-pollinated, but seed production tends to be limited this way. Better seed production has been reported from growers who cross-pollinate two genetically different Drosera adelae plants. I haven't been able to feed mine long enough to make  them to flower. 

Genetics: "Cytological studies showed that each of these species is 2n=30. D. prolifera, D. schizandra and D. prolifera appear to have evolved from a common ancestor" (Lowrie 132).

       

Propagation techniques: see the sundew propagation page
Starting from seed-never tried it, but should be easy if you can find seed somewhere...
Leaf-cuttings- work extremely well (see above left picture)- D. adelae is one of the easiest plants to take leaf cuttings from. You can obtain 30+ plants on a semi-new leaf that is 3-inches long. The water floating method works fine, or you can place cuttings on peat moss or dead/living sphagnum moss.
Root cuttings- VERY easy. You will notice plants popping up on their own from the roots even when you aren't trying to produce more plants.
Flower stalk cuttings- would likely work, but I've never tried this.
Divisions- work well. the plants tend to clump a lot since they are constantly sending up plantlets from the roots.

 
 
Top left: D. adelae leaf cuttings, floating on water near a windowsill (Note- I normally submerge the leaves- these just happen to be floating). Top right: D. adelae plantlets budding from a leaf that had been floating in water for several weeks. Bottom left: D. adelae plantlets being established on pure sphagnum peat. LFS might work better.
Bottom left: 2-month old D. adelae after emerging from large root cuttings. 


Drosera adelae Recovery Guide

First note that when D. adelae dies, it frequently comes back to life from its roots- so don't give up too early if you think your plant is dead! Other growers have reported that their plants spontaneously die for them even when other plants in the same pot are growing just fine. Sometimes, this can be caused by insect pests or fungus. However, if your first plant of D. adelae is declining, it is more than likely the conditions that are adversely affecting your plant's growth, which can end up encouraging pests or disease.

Indoor Option (easier to control)
If your D. adelae isn't producing dew outside of the cube it came in, this is likely because it needs time to adjust to its new conditions. What I normally recommend (if growing indoors) is that you transplant the sundew into a larger pot in a mix of your choice, and make sure to keep the humidity high (by using a humidity dome, terrarium, or by wrapping the top of the pot in saran). The sundews at Lowes are fresh out of tissue culture and are still growing very rapidly, so transplanting early on is the best option. Be sure to give Drosera adelae sufficient light, using a setup like this:

After a few weeks, you should hopefully notice that the tentacles on the newest leaves are developing red coloration (an indication of good lighting) and the dew droplets on the tentacles should become larger. To make your plant establish itself even faster, you can feed it once every few weeks (as long as it has dew) with small portions of food, in order to avoid mold in a high-humidity environment. 

In 1-2 months, you should see that your Drosera adelae is becoming much healthier. There should be many leaves with dew on them, and the tentacles should be pink or completely red (unless you've been feeding it a lot, which speeds up growth, and decreases the red coloration). At this time (if you want) you can gradually remove the cover or dome, and acclimate the sundew to lower humidity. If it was given enough light, it should be able to retain its dew, especially when using the tray method. If you want to take the D. adelae outdoors at this time, you will have to gradually acclimate it to its new conditions. If at any time the sundew starts to decline, bring it back to the conditions you previously had it in, and let it establish itself for a longer period of time.

If you've already followed the above advice, and your sundew still isn't doing well, then here are a few other possibilities...

The temperature you're growing your D. adelae in may be too warm for the amount of humidity and light it is receiving. If this is the case, the sundew will show signs of heat stress- the leaves will be wilted, and no dew will be produced. A rare case indoors is that there is too much light. If this is the case, the leaves will appear scorched or dry. Try moving the sundew further away from the lights.
Otherwise, it may be an insect problem. Take a close look at the soil and leaves, to make sure there aren't insects, like aphids, in the pot.

Outdoor Option (harder to control)
If you are trying to grow your D. adelae outdoors, but it is not doing well, there are many possibilities. Light, heat, humidity, and air movement all play a role in the health and dew production of your sundew. If your plant appears to be scorched, or if there is no dew on your D. adelae, I usually recommend moving the sundew to a location with full shade. Then, after several weeks (if it has recovered), you can gradually acclimate your D. adelae back into brighter lighting until you find a location that makes it thrive.

Growing Drosera adelae at a windowsill
Often, the reason sundews don't retain their dew outside of a high humidity environment is because they have been light-starved (there is very little light in stores like Lowes while the plants are sitting on a shelf for a month). The major key for mucilage production is light. However, some windowsills don't provide enough light for dew production to reach its peak (but this is not always the case!). On my windowsill (with no additional illumination), the only time my pot of D. adelae develops dew is if it is grown inside of a sealed container, with higher humidity. In the picture below, you can see the D. adelae plants I've grown by a south-facing windowsill on the floor for the past 3 years. It is inside of a glass terrarium with a glass bowl placed on top of it.
 
As you can see, these D. adelae look pretty bad- the tentacles are completely white and the only dew they have is superficial (only present in high humidity). The only benefit to this system is that I have literally not watered this "terrarium" for a year and a half, and the sundews are still alive! If a system like the one pictured above works for you, by all means, use it! It is a very easy way to grow this species.
 

Works Cited

Lowrie, Allen. Carnivorous Plants of Australia. Volume 3. University of Western Australia Press 1998. 132-135

Additional Questions or Suggestions?

Contact me at: sundewman(at)yahoo.com

Sundew Grow Guides         

D. adelae Recovery Guide