Mystery plant and growth?
by Heidi Baehr
I think this is some type of dieffenbachia, but I don't know. If you can, please identify? Also, can you tell me whether or not the taupe/tan crusty lines are a mold, an insect or just the leaf drying up?
I've had it for 6 years. I rescued it from a co-workers office. It was not quite 1 foot tall with one pathetic, droopy leaf.
It seemed to flourish after I took it home. It's been in Miracle Gro Cactus/Succulent soil in a well draining pot. I've repotted it to a larger vessel three years ago. It's in a shaded, south and west facing window corner. I'm in southeastern Wisconsin.
When it first began growing upper leaves, the lower leaves shrank a little. Then, after the first year, maybe once every 6 months, a leaf would shrink back down to nothing, shrivel and fall off.
I thought maybe this was normal to sustain energy for the upper leaves which continued to grow quite rapidly.
In the last two years or so, this leaf loss has become more rapid, and in just this last year, I've noticed this crusty, tan-colored stuff on the branches, and on the segment areas of the stem after the leaves come off.
I've been looking online and it doesn't match anything I've found. I can't find any trace of mealybugs or spider mites. There's no stickiness anywhere. It doesn't look like scale insects.
There are two small, round, darker colored areas on the stem - but they are not soft. There more like the beginning of some kind of nodule? There is no softness anywhere on the stem or branches.
Whatever this is seems to be making the leaves fall off faster. They're now starting to come away from the stem BEFORE the shrivelling starts.
I've been using an organic (basically neem oil) anti insect/fungus/mite spray which seems to slow it down a little bit, but nothing worth talking about.
I've attached some photos. A few are not as clear as I'd like - my camera just couldn't focus down to that small of an area. Thank you so very much for you help!
Hi Heidi, thanks so much for the detailed explanation. Yes, this is indeed some kind of Dieffenbachia.
The normal growth habit is to lose the lower leaves as the new ones grow out of the top, so that part is normal. My reference book suggests that if the leaves droop and fall without yellowing first, this is an indication of the plant being chilled, so possibly this is the problem.
If the plant is in a place where it's getting cold from an air conditioner, move it to a less intensely cold area.
Leaf burn has long been the nemesis of growers of this plant, and newer hybrids are chosen on the basis of less susceptibility to this, but there is still the potential for the leaves to brown.
As for the darker green 'nodes' it's quite likely that is exactly what they are; adventitious root nodes ready to spring into action when needed.
The crusting could be caused by excess fertilizer. Make sure you flush the soil through with clear water (preferably rain water or distilled water, not from the tap if your water is heavily treated, and not from water that has gone through a water softening unit) until it runs out of the bottom of the pot.
One of the biggest problems with these plants is that they soon reach a gigantic size, okay for an atrium in an office building, less desirable for a living room in a residence.
You can cut the top off and re-root it, but sometimes that's more complicated (and messy) and generally people just toss the plant and buy a new nicer one, and there's no shame in that.
Don't feel that you have to continue to struggle with it, if it's too big, and has issues.
Take the knowledge that you have gained from this experience, and use it to grow the next plant even better.
Best of luck whatever you decide.