Question
QUESTION: I work with a science school, and our 3 year old flytraps aren't doing as well as expected. I've read your online information and answer site a few times when we first got some, and a few times since. All the bloom stalks whithered. Would a little insect soap have hurt them? Even a couple of new plants donated by a parent have almost died- no insect soap on them. They have all stayed wet enough and the subsurface root clump looks okay on most of them, but it has also been really hot -  a few times above 100 degrees- and they got full afternoon sun a few times. Any suggestions? The kids are worried about their "ookie eaters"... Thank you
Irvin
Outdoor Science Exploration / Classroom Science Fun



ANSWER: Hello Irvin,

Insecticidal soaps are the worst insecticide to use on carnivorous plants due to the fact that soaps are simply fatty acids and salts... fertilizers and minerals that damage carnivorous plant soil and kill the plants as a result of altered soil acidity and root burn from fertilizer.

Temperature is also a factor since Venus Flytrap tolerance is for temperatures in the 30-100 degree range. They like full, direct sun, but high temperatures over 100 degrees are too much for them to handle for more than a few days.

Another factor would be where the plants were obtained. You mentioned that the plants recently had flower scapes that withered... this is not out of the ordinary since they flower only during the spring season, rarely keeping a flower scape for over a couple months and with each flower opening only for a couple days. By June to July the flower scape will be dying back to the ground while more traps will form in great number to replace it. If the plants were obtained from a general store they could have been exposed to any number of no-nos.. like hard tap water, low light, fertilizer, drying out, and so forth. I have seen carnivorous plants in hardware stores that have been allowed to dry in blocks of peat from which they have no recourse but death. Since you had them for three years I suspect they have flowered several times for you and you are concerned due to the scapes dying before properly flowering.

Did the plants have a proper winter dormancy last season? If not, they will in all likelihood die this season after flowering as they will use up all their energy trying to produce seeds.

It sounds like you have them outside, which is preferable most of the time, however; that high temperature might be cooking them. My situation is similar and I have lost a great number of direct sun plants where I live due to the heat. I keep my Flytraps indoors for now under 12000 lumens of florescent shop lights in a south facing window. They do well under that setup and suffer no weakening after flowering. Just be careful of mold and keep that light on them 16 hours a day and just 4-5 inches over their leaves. Most problems with Flytraps are from low light, no dormancy, fertilizer, and trying to grow them in terrariums.

Since you have had the plants for three years, it is likely the soap and/or the heat. Repot the plants in new sphagnum and either perlite or silica sand in a 1/1 mix after soaking them in distilled water, leaves and all for a few minutes to wash the soap off and give them a fresh start. Keep them slightly shaded in the hottest part of the day if you leave them outside, letting them get as much direct morning and afternoon sun as possible. Check your water source to ensure that they are not adding minerals to the water without letting the consumer know. Use only water based or neem oil based insecticides and fungicides, avoid all that have copper and soap based mixes.

I hope your school's Flytraps pull through.

Christopher

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QUESTION: I appreciate your help. Is there a way to get the biggest possible traps? I'm getting plenty of small traps, and the ones in the store appear to have just bigger ones. Are there any bugs we should not put in the traps? Once it seemed a beetle chewed its way out and left a small round hole. We've put a couple of ~3mm termites in small traps. On their own I saw a paper wasp get caught, and it was successfully digested. Should we always keep traps fed? Should water be sitting in bottom of tray where the plant cups rest? I put them in the fridge for 3 winter months. Do you suggest I rinse them in distilled water and repot now?

ANSWER: Hello Irvin,

Trap size is more relative to age and health. Mature traps will generally be an inch to an inch and a half long.

Venus Flytraps will trap and digest anything live that can be held by the trap and smothered by formic acid and digestive fluid. Some insects and spiders are able to bull their way out or chew their way free, but most succumb. I would suggest letting the plants trap their own prey and not really worry about feeding them since they are more than capable of attracting and trapping prey when they need to. Nature is best left to its own devices. Many people complain about losing traps when feeding their Flytraps only to discover the plant completely full of flies the next day with no ill effects. Never feed the plant with fatty prey items like moths and butterflies and avoid large, strong, or well armed prey. Flytraps only need an occasional insect to acquire enough nutrients to function properly. They can and will survive long periods, even years, with no prey at all. Best bet is to let the plant do its thing with only an occasional fly or two given every month or so if it has not trapped anything itself.

Flytrap watering is best when a tray of water is left under the plant, keeping the lower 1/4 of the container submerged. More than that can risk root rot and less can lead to drying out if the plant is not watered often. With a tray of water, the plant will not need watering for several days to a week until the tray is low.

You do not need to place them in the fridge for wintering unless you live in a region where their is no cold winter. Even then, the cold is only a side effect that staves off mold and keeps the plants fresh. Just leave the plants in the lessening fall sunlight and they will be slowly getting ready for dormancy. When cool weather hits, they will go fully dormantin a chilly window or outside if it is not too variable in temperature and if the temperature does not drop too low. Flytraps in nature can toerate temperatures below freezing, down to about 20 degrees, but in pots, try to keep them just above that temperature... 40 degrees is about right. A chilly window that stays around 50-60 degrees would work to keep the plants in a light dormancy, which would be fine. The problem with refrigerators is that they can lead to drying and mold in pot bound flytraps. The fridge method can and does work, it is just more risky.

If the plants are weakening already, it might be something in the soil. They should be repotted once a year at least to keep air flow to their roots and to freshen the peat so it does not sour. Reotting weak plants can work either way as they might be weak enough that they will expire from the stress of repotting, but not repotting them when they are weakening might kill them anyway if their is something wrong with their soil.

If your sure it was the heat and or inadvertent fertilizing, a change in heat level and soil might bring them back.

Christopher

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QUESTION: I live near Capitola, CA, and winters are pretty mild. Local garden shops don't seem to offer peat moss without fertilizer added. Can another potting medium work? The traps seem to attract small long-legged spiders so if I need to demonstrate, I'll use one. The peat probably should be replaced but feel I should find pure peat moss. Thank you

Answer
The best peat is the sphagnum peat moss in large 2 foot dry bales that usually state Canadian and are wrapped in plastic. Such moss is usually free of fertilizers and lasts as long it remains dry until use. I usually find such moss in plant nurseries and garden centers. Never use small bags of prepared moss as you have already surmised that they usually add fertilizers. You might also try some of the online nurseries that sell peat and long fiber sphagnum moss for orchids and such.. just ask via email if they have unfertilized moss. Another very viable option is to visit online specialist nurseries like Sarracenia Northwest and order some of their already prepared mixes for carnivorous plants... guaranteed to be fertilizer free since they use it on their own plants.

Christopher