Shelob Tolkien - leaves slowly turning yellow and dropping

[Spiffy]

Hi All...wondering if anyone can help with this plant.

I purchased back in Sept and plant looked healthy and with a flower spike. Within a couple of weeks the flower spike died off and the first set of leaves dropped.

I figured it may be too cold or not enough light, so moved it under a grow light in my kitchen, which is a bit warmer (say 14c - 20c daily variation). Humidty is 60-90% (gets steamy when cooking!). The grow light is decent and we have a chili plant and herbs also growing under there. The plant seemed to be doing better and a new bulb growth has appeared.

Attached are 3 photos. First from when I bought it, the 2nd two from this week where it looks like it's going to lose another set of leaves. I'd just watered it over the weekend so now I'm suspecting it's either our water or fertiliser that is giving it grief. I use a mixture of tap and rain water, depending what's on hand. Fertilise monthly. Roots look fine and even showing some new root growth.

First time growing one of these so not sure if anyone has any tips? Successfully kept Nepenthes, Phals and Paphs so a bit stumped on this one! Main issue we have is living in a cold draughty house in the UK, so can be cold and not much light in the middle of winter. I thought these plants were supposed to be relatively forgiving!

[aliceinwl]

It could just be a combination of it aging and adapting to new conditions. I have a bunch of similar orchids and it’s not unusual for mine to jettison some of their older leaves as they settle in. They’re most likely to drop leaves if there’s a big difference in light (especially if you’re growing in higher light levels) or temperature from wherever they used to be. The roots look good and I can’t see any signs of rot. I would tend to take a wait and see approach: if it’s making changes in response to the conditions it’s now being grown under any more big changes could set it back.

[Leafmite]

I do not grow this particular one and it has been a while since I grew a bunch of Oncidiums and felt like an expert with them (I have just one, currently). I cannot absolutely be certain what is happening but I think that it might have been stressed from shipping and is now starting to recover. It is losing leaves from the old growths but getting a new growth (so it is adapting). The roots look good, the pseudobulbs are all nice and plump...I think your orchid is alright.
As for fertilizer, just make certain that you flush the pots well once a month to rid the medium of any unused fertilizer to prevent it from becoming toxic. If you are using mostly rain water, you might need to make certain your fertilizer provides all the nutrients your plant needs (Calcium, magnesium, iron, etc.). The rain water should always be room temperature when using (something I always need to remind myself, especially in the winter).

Hopefully, others will add to this. Good luck!

[Dollythehun]

I have a similar plant. I was told by a former member that they need a lot of water and light. I water when my mix approaches dryness and give warmth (70-75f) and catt level light. My plant never gains appreciable size, it grows a bulb and loses a set of leaves, while the bulbs remain green (and red speckled,) and it blooms every year. This is not a favorite plant of mine. These are just my observations. It may not be your care, it may be the plant.

[aliceinwl]

I think they’re pretty versatile. The one I have is a NOID but looks identical to Shelob. I too water when it approaches dryness and it gets plenty of light. I grow mine outside and this is its second winter. I bring it in at night when frost is in the forecast but otherwise it weathers lows into the mid 30s fine.

[SouthPark]

The newest photo shows a new shoot growing, right?

Assuming the temperature range you mentioned is from 14 to 20 degrees ---------- that should be fine.

Notice the black-coloured blemishing on the leaves. Maybe that's typical - but something to consider too - ie. is it fungal activity?

If there's no pathogen attack occurring, then could focus on lighting duration and lighting level. It sounds like your growing area has good air-movement, so that's good.

Anyway - if that is a new growth, and if it keeps growing nicely, then that will be great news.

[Spiffy]

Hi All...thanks for the feedback. Sounds like a case of hanging on in there. On the plus side it's starting to feel a bit more like spring around here, so hopefully the warmer temps and increasing daylight will mean I can shift it to a warm windowsill in a month or so. Fingers crossed it will keep its last set of leaves while the new bulb is growing out!

[Spiffy]

Well a somewhat happy ending to this story. My troublesome plant managed to grow a spike and provide a bloom!

Sad as it is, I must admit to being a little underwhelmed. The flower is tiny and doesn't look like there are any more on the spike.

I look online and compared to some other shelobs I've seen, possibly this is just a duff version. Likely I'll let it fill out the pot and decide what to do with it then. Windowsill space is getting to be quite a premium!

[estación seca]

I didn't see this thread earlier. Let's start with how intergeneric Oncidiums grow. Most people buy a plant in flower at a market, so I'll start there.

The spike or spikes formed on the newest growth or growths. The plant is still juvenile, and was grown to be sold with its first flower spike in full bloom. The plant is in a pot that is full of roots, and old medium beginning to break down.

The plant should be repotted at the next appropriate time. As with almost all orchids, the best time to repot is when roots are just beginning to form.

Oncidiums have fine roots when compared to Phalaenopsis or most Cattleyas. In general orchids with fine roots should never dry completely during their growth period. This is different advice than is often given for orchids with larger-diameter roots.

Because these are sold as immature plants, if they are given proper care, future growths and future flowering spikes should be larger with each growth cycle, until the pseudobulbs reach full size. In the case of Shelob, pseudobulbs can grow to be about twice the size of the ones on your plant. It is a very large and impressive plant when grown properly.

Most flowering intergeneric Oncidium hybrids sold at markets have been cared for carefully, so they look as good as possible. That means appropriate temperatures, light and humidity, and never going completely dry at the roots. Under such care they retain leaves for several years, and almost every pseudobulb will have a full set of green leaves.

This kind of orchid makes new roots and spikes only from the newest growth. Older growths do not make spikes and do not make roots. After the flowers on a spike open, some hybrids begin to make new growths almost immediately. Others wait a while. Whenever it happens, new shoots will form from the base of the newer pseudobulbs.

In some hybrids the roots will form at the same time the new spike is just visible; other hybrids wait a while. But new roots always form with the new shoot. This is the time to repot. Some people repot all new orchids immediately; I don't do this routinely. For intergeneric Oncidium hybrids bought in flower, I wait until the flowers have finished and new shoots are growing. This means I may need to water carefully because the medium is getting old and nearing decomposition. New root formation on new shoots can be prodigious with proper care, and will quickly fill the pot.

Some hybrids form the spike while a new growth is just beginning; others, sometime during development; and others, only when the new growth is mature. Flowering occurs, and the cycle repeats.

Some hybrids will continue to make growth cycles all year if temperatures and light are adequate. Others make 1-2 cycles of new growth per year.

Now to your first post. Once taken to a new home, they are usually in a situation less perfect than the grower's greenhouse. Plants frequently drop leaves on older pseudobulbs the first time the new owner forgets to water. This does not affect survival of the plant if conditions are still tolerable. Flowering will still occur, but not be as impressive on a plant that gets suboptimal care.

I think this was happening around the time of your first post. The plant was in flower in September. It made another growth that was smaller than the previous growth. It is common for these plants to drop leaves on older pseudobulbs when stressed by insufficient watering, too much heat, too much light or too low humidity. Your plant is very yellow, and leaves dropped. These plants when happy are typically medium to very bright green. I suspect your plant was getting far more light than it needed, and much less water than it needed. As an aside, that amount of light is also far more than Phals should have to grow and flower best. It's not often people in England are able to give their plants too much light, but I think that's a large part of your problem.

If you repotted at the wrong time (I don't know whether you did), there would be root damage. There would be no new roots until the next growth cycle. That makes it harder to water the plant adequately.

The root photo from your first post shows a weak root system. This also suggests to me underwatering. That pot should have been full of roots from the growth that formed since you got it.

In the recent photo you show, the new growth is even smaller than the previous growth. The flowering is unimpressive. This is still a young plant; with proper conditions that growth should already have been at least 50% larger than the previous growth, and the spike much more impressive.

So I conclude you should change some things. I would recommend watering more often. Don't let the pot dry out completely.

Put the plant into less light. Aim for pale green with no trace of yellow on the most recent growth. Older growths may change from yellow back to green, or they may not.

I haven't mentioned fertilizer. It can make a big difference, but only when other conditions are good. I would fertilize with a small amount of fertilizer in each watering during active growth, and not fertilize during periods when the plant is not making growth. If you have a fertilizer like 20-20-20, I might suggest a quarter teaspoon / 1.25ml of fertilizer powder per 4 liters of water at each watering. Begin as soon as you see new growth.

The good news is that these things grow so fast, the next growth can be near perfect. And it is much easier to convince people to water more often than it is to convince people not to overwater.

[Keysguy]

I have a Tolkien growing in my shadehouse. I've had the plant for a long time (10 years +/-) and it goes through good phases and bad phases. I don't know what it is with that plant but I just can't seem to make it consistently happy and honestly, I keep thinking about pitching it. I have too many happier, prettier and more interesting plants to let it take up space that is probably better used for something else.

That being said.........listen to seca's advice.
I don't know if it's too much light or something else but those backbulbs should be bright green, not yellow. Concentrate on that newest growth and when you repot it get rid of most of those backbulbs. They are sucking energy from the plant for no value.