Drosera : Basic Care (part 2)

Drosera / Sundew

Soil

Sundews evolved to eat bugs to make up for the nutrient poor acidic soil they naturally live in. Regular dirt or potting soil kills sundews fast so we refer to the "soil" as "media". Do not fertilize. I use 40% Sphagnum peat moss and 60% perlite, sometimes 1/4 part silica sand. You can mix in 25% long fibered sphagnum moss and/or use it for a top dressing if you like. I like doing both with Sundews. Make sure you get pure Sphagnum peat moss, you don't want Miracle Grow or any other chemicals mixed in with it. Please see the soil section for detailed information on the various types of media to use with carnivorous plants.

If you use sand make sure you use silica or quartz sand. Make sure you don't inhale the dust from the sand though. You can grow almost all of the Sundews in pure long fiber sphagnum too, some sundews prefer it. Watch how wet you keep them if you use 100% lfsm, it can easily keep them too wet. Play Sand and River Sand will add nutrients to the media and therefor kill your plants.

If you don't use sand make sure over half the mix is perlite, 40/60 or 30/70 peat/perlite. This mix is acceptable for sundews and flytraps. The perlite allows for plenty of air pockets and good drainage which helps keep the roots from rotting. If you use medium perlite (only available at specalty shops) then 50/50 peat/perlite is fine. Generally fine perlite is all your going to find locally.

The majority of small pre-moistend peat bags are contaminated. Get the dry sphagnum peat moss that comes in bails. Look for big green bags that say Canadian Sphagnum Peat Moss because they harvest it responsibly. Break it up into a loose mix and pull the larger sticks/twigs out of it before use. The small bags become contaminated, at the very least, because they moistion it with tap water. Since they also produce fertalizer at most of these packing companies they can become cross contaminated too. So, if the small bags are your only option rinse and drain numerous times before use. You can NOT rinse out Miracle Grow and it kills.

Light

Some Sundews do not require bright light, but not many. D. Adela can survive happily in fairly low light conditions. Sundews generally grow in the shade of another plant or other obstacle in the wild so direct sun is generally not needed. Bright shade to partial sun generally works fine.

I grow most of my sundews under fluorescent lighting. Since most of them are low growing they do great under a shop light or in a terraruim. If fluorescent is the primary source of light use two 40 watt cool white 4' bulbs within 10" - 14" over the plant. An economical shop light works well for this. Put the light on a timer to go on and off with the sun. It doesn't have to be exact, I generally run mine an extra two hours. But it does need to change with the seasons so they can keep track. Light is the main factor in them determining what season it is.

Optionally you can use the compact flourescent bulbs if you only have one or two plants. Get the ones that have a 100 watt output and say "Daylight Bulb" on the package. Otherwise it produces an orangish light that isn't as good for the plants. Keep the same distance away, 10" - 14". I have found that shop light hoods do well for this, you can generally find them in an automotive department. They have a large sheild, 10" - 12", and a clamp for a mounting bracket as pictured.

Most sundews will have reddish glue drops if they are getting enough light and some will develop color in the leaves. So long as they are producing dew the light is generally fine, some produce clear glue drops.

Direct sun and/or excessive temps can burn the dew off sundews. But most will acclimate fine into full sun, or close to it, if given a chance. If your growing them inside and they are not producing dew then increase the light, either in intensity or time span. Whichever you can do, until dew production begins. Rarely no dew comes from the media being too dry, if this is the case its way to dry. Watch the leaves, short tight compact plants mean to much light, or the plant is spending all of its energy producing more plants. Long thin (stringy) leaves or all green leaves generally means not enough light. Signs of to much light are leaf tips turning brown (also a sign of low humidity, rarely with sundews though) and yellowing of leaves or red spots on the leaves. The leaves generally get red splotches, then turn red, then brown and die prematurely. If this happens to old leaves its often not a big deal, but new ones should do fine. If the new ones still have problems you need to reduce the light. Proper acclamation will prevent burning, or at least minimize it.

Humidity

Humidity is not a huge issue for most of the sundews. Light is what gives them the ability to produce dew, not humidity. Generally 35% and better is fine once they get acclimated to it.

Dormancy

Some Sundews do not require a dormancy. When at all possible look up the area where the sundew grows naturally. This will tell you what kind of dormancy, if any, is needed. Sundews that do go dormant generally require 3 - 4 months of winter dormancy, triggered by a shorter photoperiod and temperatures below 50°F. Once dormant Sundews require very little light and must be kept much drier (never let them dry out), a rare few do actually need to dry out. A garage or shed makes an excellent location for dormant plants. Most dormant sundews can tolerate temperatures down to the middle to upper 20°.

Reference : Drosera Care