Ponytail has thin light stripes

Hi. In short: I am checking up on my Ponytail "palm" (Beaucarnea recurvata) which I got 1½ years ago, and one peculiarity which I can't find a good explanation for is the light, thin stripes you can see in pictures No. 1 and 2.

Longer version:

Background: I didn't worry too much about plant healt until 1 month ago (had a basic book, asked friends & stores, that's about it). I had some pest problems that ended 3 years ago and haven't bought any new plants since then. Until 1 month ago, when I also tried to read up on repotting and all other care issues, tired of having plants that slowly die one me, it would be nicer if they were healthy and got bigger, especially since I like palms and other exotic plants.

This Ponytail has received water in small bursts until 1 month ago (meaning only the top inch or so is likely to ever have been wet), when I decided to thoroughly moisten all plants' soils, and not water again until it is just slightly moist (more on the dry side for succulents like this), aided by a cheap moisture meter (and other methods, since the meter isn't completely reliable). It sits in a bookshelf, energized mainly by a 12W flourescent light bulb with reflector which used to be at ~1' distance but since 2 months at 1/3', giving up to 10 klx at the leaves; it also has a northern window 3' away. I know it prefers more sun, but I tried this with another Ponytail long ago without the lamp and it got the characteristic "hippie hairdo", but this one does not, it still has the perky look it always had. 1 month ago, I changed the top ~½-1" soil.

Health review: It looked to be in very good shape (to my defense it's been on a shelf so I couldn't look closely without standing on a stool), besides brown tips on some leaves but not so bad. But when I looked closely I found a few symptoms I tried to understand:

• The thin, light stripes, beige color, looks like it is dried out in that small stripe, it is visible on both sides, about 20 leaves have them, some have two, length between 1/5" and 1", not on the newest leaves. No indications on insects or pests or anything, no hole thru
• Several leaves (a dozen) are "bent" more than what I've normally seen in pictures, but I did find the picture below from Wikimedia/"Botanical Garden Karlsruhe, Germany" with similar bends. I can imagine that the fact the leaves cross-sectional area is U shaped makes it more prone to being bent and the fact that the older leaves are a bit thicker. But many of the "light stripes" coincide with these bends, I guess both indicate some mechanical weakness and maybe one can cause the other. I haven't thought much about this before, but I took a picture after I changed the top layer of soil and as you can see some were bent then too (maybe fewer) see 3rd image.
• All new leaves are brighter green, and so are the beginnings of all leaves, and most new leaves are quite narrow, but I checked in a shop today and apparently this is normal (even though mine might have a bit more of this, but it's no big difference).
• I'm not sure I want to continue watering until it's thoroughly wet. I did it 3 weeks ago and was happy to see that after a few days (almost a week) it was almost dry again. But I watered it again like this 3 days ago and it's still quite wet. I read that the most important roots are on the sides and shallow anyway, and that it can easily produce new roots if damaged. I'm worried about root rot. There are no yellow leaves but I investigated the soil and roots 1" deep, of the 3 roots I found with diameter ~1/30" 2 were white (or light beige) and one was white after i scraped it with my nail; there also were much thinner roots which were darker. I read a sign of root rot is if the soil smells like mold, fungus or wet sock, if I stick my nose in it it smells very slightly like mushroom which I guess could be a bad sign?
• It has a bunch of small, gray spots on some (older) leaves, only at the inch closest to the meristem, only on the top side, and it can't be wiped off of scratched with my nail. See last image.

My plan for now is to first put it in better light until the soil is dry (not moist), then flush it with pure water to remove excess salts, and after that water it with ½ dose of fertilizer. And as soon as it isn't wet anymore, I will move it back to where I want it to be, and after that I plan to water it only from the top so that the top ~1" gets wet (to get all the soil wet I have to let it sit in water plus water it from above about 10 times, due to the nice looking but annoying bonzai-like pot). I think the idea to thoroughly moist soil for all plants sounds good but the exception to the rule might be a Ponytail in bonzai pot with low light situation.

Regarding the thin light stripes I'm thinking it can't be bugs or pests, underfertilization not probable since it need almost no fertilizer from what I heard, I'm thinking of things like too much water (even root rot), too little water (not lately though), too much fertilizer (will flush soon), or possibly that stabbing the soil with the moisture meter probe might kill off roots (seems less likely since it's pointy and I read it creates new roots easily). Low light I haven't heard can cause anything like this? Perhaps the bends are for the same reason? And I hope there is no reason to think there might be root rot (the smell being the only, weak indication I can find so far).

http://upload.wikimedia.org/wikipedia/commons/2/2b/Beaucarnea_recurvata_001.JPG

All input is welcome. Right now it looks ok but I fear it might get worse if I don't understand it. Thanks in advance.

OK, David, here goes. First, a caveat. Though I am a so-called expert on many tropical plants, I am no expert when it comes to Ponytail Palm. I grow them, but they are simply "novelty" plants for me.

That huge, bulbous trunk stores water, lots and lots of water. These plants can go months without water, though I would mist the leaves regularly. More on that later.

This is what I would do:

1. Remove the plant from its pot, and I know, that's a chore. You really need to see what the roots are like. If you find lots of rotten roots, or only healthy roots, this will tell you a lot. Roots are everything!

If a lot of the roots are rotten, remove them. Rotten roots only act as water-holding sponges, and your plant won't like this. Rotten roots will also tell you that water is the problem, or at least the major problem.

2. Your plant needs extremely well-draining soil. I use 1/4 potting mix, 1/4 coarse perlite, 1/4 pea-gravel, and 1/4 medium Douglas fir bark. Anything that is similar to this should be ok. You just don't want the soil to hold water. Also, if you have a water-saucer under your pot, be sure to empty it of water. Your ponytail does not like "wet-feet".

3. I water my ponytails once a month and I water it well, until water flows out the drainage holes. I also fertilize my plants every-other watering, using general purpose fertilizer but at 1/4-1/2 the recommended dilution. Thus I would water my plants in January, fertilize in February, water in March, etc. I am quite sure you could do this every two months rather than every month, but since I grow so many tropical plants, the ponytails are on this schedule simply because it is convenient for me.

4. If your house has central A/C and heat, there will be little water vapor (humidity) in the house. That's where the misting comes in. I would mist the plant every few days if possible, but at least weekly. Some of the leaf streaking could be from dry air. Also, IF your plant is directly under a register, move it. That hot and then cold air just dries the leaves out too much.

5. Your ponytail needs strong, indirect light. It is now so large that a single light source is simply not enough. Also a north exposure is absolutely the worst of all the exposures. East is best, followed closely by south, then west, and (badly behind) then north. With an eastern or southern exposure, let your plant have direct morning sunlight. With a western exposure be careful of the sun from noon until 4:00 PM. That sunlight is extremely strong and can sunburn your plant's leaves. With a northern exposure - well, your plant will never see the rays of the sun!

OK, that's about all I know. Much of this is what I would use for a lot of my orchids, though orchids would get more frequent watering because they can't hold the amount of water than your pony-tail does.

Ken

Thanks Ken. Sounds mainly like I should take a look at the roots, and then be ready to change soil. The soil probably is well draining except for the top ½-1" which I put there a month ago which is ordinary soil mixed with some sand. I thought the top inch is always dry first anyway in all pots. Should I look at only roots with diameter > 1/30" or so, or also at the really tiny hair-like roots? And if there are rotten roots, I suppose the soil is full of fungus so then I really should change soil and perhaps wash roots in water first? Does the smell indicate fungus or does it sound like nothing?

Some small notes: It is not close to any register or radiator, and no AC in that room. The humidity is not so bad now in spring (~40%), was worse on some winter days. I already use 1/4 dose fertilizer. I've always emptied the tray. Forgot to mention that I had the lamp on 19h/day but I changed that to 16h a week ago (some keep it on 24/7, but I think 16h will have to be enough).

I read somewhere you shouldn't mist succulents except maybe once per year (to get rid of dust), doesn't that apply to the Ponytail? (And some say you shouldn't mist at all in winter - but that's when the air is the driest, I guess the jury is out on that one.)

I was hoping someone had seen similar light stripes. And about the bent leaves, I wonder if Ponytails usually have this distinct U shape for cross section.

The odor may simply be from a non-draining soil. You are right in that the top 1" of soil will be the first to dry out. Don't worry about the fine, hair-thickness roots. If the major size roots are rotten there will be no fine roots.

I will try to find the time to go out and take some pictures of a couple of my ponytails. Mine are perhaps half the size of your and my leaves will not be the same as yours. My ponytails get a lot of strong filtered light since they have been facing the south side of one of my greenhouses. The bright light causes the leaves to turn reddish. So don't let that coloration confuse you.

In my opinion you have the humidity situation turned upside-down. Tropical plants love humidity. The more the better. Here in the deep south, when our relative humidity gets down to 40%, many people get nose-bleeds! Our humidity averages 85%!!!!

I spray/mist my ponytails pretty much every single week. They are growing with all my other tropical plants, so since I am spraying the others, well, I just spray the ponytails. That's all year long. Keep in mind that even the ponytails that grow in the high deserts of the world, dew falls on them regularly. That is mist. The water on the leaves dry out during the heat of the day. It is not the water on the leaves you have to worry about, it is water in contact with the roots for too long a period. Ponytails are still tropical plants and the vast majority of tropical plants thrive on high humidity.

Since you have to supplement your light and I do not, I really don't know enough about artificial light to guide you there. I do use fluorescents in my greenhouses (16, 48" ones in each) and also use LED lights in my "Orchid" greenhouse, but these are all on timers, and the lights stay on from 4:00 PM until 10:00 PM. I am about to turn all the fluorescent light off, today in fact. The greenhouses get enough sunlight so artificial light is of no value. I will use the LED's as usual since they are helping my "baby" orchids and bromeliads grow.

I wish I knew more about ponytails, but as I said, I only grow them as "novelty" plants and haven't grown enough of them to know the finer points of their care.

Ken

One thing just struck me: This plant has never ever had any brown or yellow leaves (sure some tips but not much of it), so all leaves are still there, and new on the way. If I look at pictures of older Ponytails on the web, some have quite short "hair" but I suspect those have had their stems cut not too recently, if I look at old trees in their natural habitat, the "hair" is always quite long, looks like 3' and more. Comparing it to mine, I don't think it has any tendency to grow longer "hair" as a complaint towards low light. And the only way a plant could keep very close "hair" would be either if old leaves are regularly dropped or pulled off, or if it doesn't grow at all. Cutting the stem as short as mine from that perspective seems stupid, it looks great in the store but I can't see how it can keep from reaching the floor very soon. I could trim off some older leaves but it wouldn't improve anything since the longer leaves are both among the oldest and the relatively new. I could cut the ends but if I do it too much it doesn't look very good. Perhaps I will have to cut the top of the stem every few years to keep it within reason? And every time I cut it would get even shorter... Seems like the idea to cut the stem in the first place was a bad idea? Could I perhaps cut off one of the three buds every year or so and hope a new one comes soon? I think cutting the stem makes it grow new buds but I don't know if cutting buds induces the same reaction?

And another thing I just thought about is that if I have my lamp as close as ~4" like it's been last month, the lower halves of the leaves don't get any light at all almost (the still don't get much if the lamp is on top, no matter what distance, spreading angle is ~45deg). Wonder if that could affect things like the bent leaves - perhaps the plant decides these parts of the leaves aren't very useful and withdraws stuff from it? Seem hard to improve this. Quite hard to cover all parts of all leaves with one lamp. Today I have a lamp holder with white background inside it, perhaps a brighter reflector, which makes the light spread less, might be a big improvement.

From what I read Ponytails (though preferring lots of sun) accept very low light for months, BUT perhaps what I should do is put it in bright sunlight for 1-2 months in summer. Can imagine it might help. Wonder if I should move it very gradually (like 1 week with full indirect light, then 1 week with direct light half day, then full direct light, and also ramp down) or could I ramp up/down more quickly? The normal place will have to be in the bookshelf though, there's no permanent room close to a window, but I can send it on a summer vacation in the sun.. :)

When the soil isn't thoroughly wet and I don't poke around over an inch deep it doesn't smell anything even with the nose in it so maybe it's nothing.

Misting doesn't affects air humidity noticeably in an apartment unless you do it at least every hour or so (I know, I even made measurements, it also doesn't work with aquariums, pebble trays or humidifying machines, the ventilation removes all humidity too quickly), but plants may still like getting the leaves wet, I don't know and haven't read anything about the water on the leaves in itself being appreciated by the plant (without considering the indirect way of air humidity). Currently I'm trying out misting most my plants every morning (not succulents) to see if leave quality is affected. And you pointed out dew as a natural way for the Ponytail to get wet even in the desert so maybe I should mist it every morning (or week?) as well.

All in all it looks quite good and hopefully is in rather good shape. Wish I understood why the stripes are there though, and why the leaves are bent.

I can tell you that IF you put your ponytail out into full sun, the leaves will be badly damaged (sunburned). You could do this in the fall/winter months (in mild temperatures) simply because the sun is so low in the southern sky it is not intense enough to burn most plants. In the spring and summer place your plant so that it will get morning sun, but no direct sun after 11:00 AM. Every week or so you can move the plant where it will gradually get more sun. Keep in mind, just like my plants, the leaves will gradually get red-tinged. I like that color but IF you want to keep your plant with bright green leaves, limit the sun exposure.

Humidity trays and misting are NOT supposed to raise the humidity anywhere but adjacent to the plant(s). After all, all you want affected are the plants, not the house/apartment. You would probably need multiple Gro lights for your large ponytail.

Ken

I think the soil is ok now. When it was very dry, I flushed it for a long time with a shower (the new soil I had put there left the pot with the water), after that I could see the old soil had quite a lot of ~1/20" grit so it probably drains well, and no smell of mushroom anymore. I dried the stem with a hairdryer (!) except the lower ½" which was impossible, then I added a ½" layer of soil which was a mix of 60% normal indoors flower soil (95% peats, 5% sand) and 40% 1/10" pebbles (I had peats + 20% sand before but when I think about it, I'd say peat mixes better with small pebbles than sand, just my own thought). Didn't water any more. I read these plants also can get stem rot at the lowest part, I hope this will give proper drainage. (Still when I think about it, I can't see how the pebbles can make the peat give up the water more quickly. Sure it will allow oxygen to a large portion of the roots, that's probably great, but I'm not sure it will keep the stem from being moist for days.) Also moved it, will give it maximum amount of indirect light for a while, and maybe direct sun for a short while, see how it reacts. Already got some purple leaves..

I'm still hoping someone has an idea why there are these pale stripes, and bent leaves.

PS Off topic: Humidity trays etc do not work in living areas because the ventilation counteracts it very efficiently. I did various tests, such as putting a humidity meter INSIDE a bucket half filled with water, it went up from 42% to 45% only. And if you put the meter an inch above the bucket, humidity is the same as without the bucket. So any pebble tray or aquarium would do even worse.

David, I never use pebble trays or the like. The vast majority of my plants are outside, and those inside are only there to enjoy there flowers (orchids). Needless to say, here in the deep south, lack of humidity is the least of our problems.

I know many people that grow their tropical plants inside. Many grow them on racks with overhead fluorescent or LED lights, and most of them use humidity trays. They swear their plants don't do nearly as well without those trays. I don't know. All I can do is report what is told me. To me, unless the humidity tray(s) are near a return and/or the central AC/heat is running the majority of the time, the humidity has to be higher near those trays. But that's not a scientific answer by any means. If you don't think they have value, by all means don't bother using them.

I still think your pale stripes/bent leaves are results of all the things I have mentioned.

Ken