Nobile Denbrobium Himezakura

[Sharyn]

I have a dwarf Den. Himezakura. It's growing and has developed 2 new leaves recently, however, everytime I water it, I have a yellowed leaf next day. A few days later, the leaf will fall off. Then, everything is fine until after the next watering.

It's in a west window (filtered light). I'm using 1/4 strength fertilizer, room temp. water. Is this normal or should I stop fertilizing right now? I thought I should resume fertilizing as the plant is in growth but apparently it doesn't like it. It's planted in small bark, perlite, and charcoal. I thought I was doing everything right, but I can't figure out why it keeps getting a new yellowed leaf after each watering.

[Lucinda Brown]

Usually,a yellowed leaf[if no mites are present]means it just got watered a little later than it needed it.How often or far apart are you watering it?

[Sharyn]

Lucinda: It's quite possible that I'm not watering enough. The skewer is still slightly moist from the bottom of the medium when all else is very dry. Our weather here has been mostly chilly and rainy, 40-60F and the orchids don't seem to be drying out very quickly. I think it's being watered about every 6-9 days. I'm a little skiddish about watering too much & rot it out.

[kmarch]

Nobile types grow and bloom according to a distinct annual cycle. They grow new canes in spring-summer during which you should give them lots of water. New canes mature in autumn at which time you should taper watering down and let the plant get cool. In the winter give then lots of sun and keep them on the cool and dry side, watering maybe only a little every 2 weeks or so. They will then bloom in the late winter. I do not fertilize my nobile types at all as too much nitrogen causes them to keki instead of bloom, although some folks I know do fertilize when the new canes are growing. It is not uncommon for canes to loose their leaves after 2 years.

My apologies if you knew all that, I wanted to go over it for the benefit of anyone who may not have known about their growth cycle.

So now I have a few questions:
1) Are the yellowing leaves on new growths or old growths? - If they are on old growths there may not be any cause for concern as it is not uncommin for old growths to loose their leaves. If they are on the new growths, it may be a problem (see below)
2) Are the new growths just starting or more advanced? - As it is spring for you in the Northern Hemisphere, and according to the plants usual cycle, it should be just starting new growths. Also as winter has just finished for you and it sounds as if you've been fertilizing and watering in the winter, the plants cycle of growing and blooming might be thrown off. If that's the case it may not bloom for you this year.

That's probably enough questions for now. Let's see where this gets us.

[Sharyn]

Thanks Kevin. This information should be helpful to everyone growing dens.

In answer to your question, the three leaves that I've lost were older. The new leaves have formed within the past month (2 new leaves, & 1 still coming out). The roots on top of the media are quite dry but I've resisted misting them so as not to overwater the bark. It's been chilly & very damp here for several weeks.

This yellowing problem is only with this particular den. and it's a compact and my only nobile type. The other dens. are all doing fine - just regular dens.

You're right that this plant was fertilized over the winter (stopped as soon as I realized they're suppose to be dry & no fertilizer.) I may have learned this lesson too late. I'm ok with the plant not blooming this year. I'm just trying to keep it from losing more leaves, especially during it's growing season.

From what I'm gathering from your comments, this nobile may have to start over again with it's growing & resting cycles. Is that correct? Thanks again for your advice.

[fred]

I just thought that I would go over some link,s to help out with Den,s

http://www.orchids-care.info/dendrobium.php

http://www.alohaorchid.com/DendrobiumIntermediate.aspx

http://www.orchid--care.com/

http://www.easy-orchid-growing-tips....um-orchid.html

http://www.how-to-grow-orchid.com/de...rchid-care.htm

http://orchidcare.com/dendrobium.htm

http://about-orchids.com/pLog/index....Id=17&blogId=1

http://www.orchidco.com/downloads/dendrobe.pdf

http://www.brennansorchids.com/dendro.html

orchids in the home link

http://www.orchidco.com/downloads/orchidsinhome.pdf

[Sharyn]

Fred: This first link has information to give Dendrobiums high nitrogen. The article says 29-9-9 year round! I think this is why some of the members are confused about fertilizing dens. (including myself).

[fred]

They are all links from around the world as for me down here in Tasmania I only Fert once a year.
I use a little Dynamic lifter placed on top of the Medium (not on the plant )
I water the Dymanic lifter with a light spray and once a week I mist that as well so my Den,s get a small amount.
I put that on this time of year.

I also know of a large Den grower who does realy well with his Natives and he does not use Fertilizer on them at all.
Some also have told me that they use Sheep poop the same way I use Dynamic Lifter.
I hope this helps you

[arleneg]

Sharyn,

I suggest using a balanced fertilizer on the Dens. That's what I used on mine (now trying worm tea ). It's healthy and still has the blooms from several months ago! But then, I have mine sitting on a windowsill where it gets lots of light...

[Sharyn]

Worm Tea - Sheep Poop - Yikes! I don't even want to know where Fred lifted that Dynamic stuff from. What is it?

Arlene: I have an order in for some worm tea. I'm going to give it a try. Since it's organic, I doubt that it could only help, not hurt.

Fred: Really, what is Dynamic lifter?

[fred]

Sharon you are funny
Here we can get Dynamic Lifter most large super markets also fron a garden nursery,s.
sheep poop well I will not go there lol
I buy that here from the farmers.

[kmarch]

Hi Sharyn,

Allow me to take us a few steps back and hopefully clarify some things. The genus Dendrobium is one of the largest among orchids with something like 1200 or so different species. They come from wildly diverse climates, from cold and humid/wet to hot and dry and literally everything in between. And over the centuries they have adapted well to these different climates. When we grow these in our homes and greenhouses, we try to give the plant more or less what it would get in the wild. Because Dens come from so many different climates and have such different growth cycles there are a dizzying array of recommended approaches to growing them. High nitrogen, low nitrogen, water all year, dry winters, etc., etc., etc. It's staggering and it should be no suprise people read different things about how to grow and get confused. The reality is that all of those approaches are right, but only for a certain kind of Dendrobium.

There's GOOD News Though
All you really need to know is how to take care of your Dendrobium, in this case a nobile-type (also sometimes called a 'soft-cane' Dendrobium). I recommend being selective about what you read, or rather what you take to heart. If you're looking for cultural info on nobile-type, then feel free to disregard cultural info that is not meant for nobile-types. If someone says to me, "I grow my Dendrobiums....." I always ask, "What kind do you grow." since there is no one-size-fits-all for this genus.

(By the way, Dynamic Lifter is an organic fertilizer sold in Australia by Yates - Yates is like an Australian Ortho)

Hopefully this clears up some of the confusion regarding Dendrobium care in general and the care of your nobile-type in particular. I believe the fairly standard rule-of-thumb is to avoid giving nobile-types high nitrogen fertilizer and to not fertilize at all in autumn and winter.

Keep asking questions!

[Sharyn]

Kevin: A very heartfelt thanks. You've helped to clarify this Dendrobium saga for me. Now I understand why one of Fred's links called for requirements of which I wasn't familiar. I've noticed that many of the culture/care links and Orchid grower's sites give a lot of helpful and general information, but often are not specific enough for the particular orchid in question. I guess that's why so many of us rely on you and other more experienced growers to help us out. Thanks again. I'm sure I'll be back in the fall with more questions on this one.

[E-Jag]

This is pretty good stuff. As regards Kevin's comments about specific care for specific dens, is there a way to tell a nobile from a phal type den if the plant isn't in bloom? I've no idea what mine are. Thanks again.

________________
E-Jag

[Anton]

Dynamic lifter is the carcasses and dregs left over from chicken processing, they are mulched up and mixed with some other (you don't want to know whats) put into big ovens and burnt to a crisp.

The dried stuff left over is then put through pellet making machines.

Believe me, the stuff stinks to high heaven sort of like fermented cow manure, country folk would know what I mean here.

But, this stuff in unbeleivable as an all round fertilizer, lawns, pot plants, trees, you name it. Nearly as good as worm poo.

Speaking of which, I have found a big garden supply company here in Adelaide that sells worm farms all set to go.
For the Ozzies, this was Stratco, so I wonder whether they sell worm farms interstate too?
I can put you onto the worm breeders if you are interested, you buy the farm hardware and then contact this mob to get your worms.
As far as I know, they ship interstate too.

[fred]

That sounds good to Anton.
I will give the worm farm a miss as it is to tempting to go fishing lol

With the Dynamic Lifter I also soak that in a bucket of water for 24 hours and strain that into another bucket and mix that again with water like a week tea.
I have found that also works pretty good.

[kmarch]

Dear E-Jag,

Fortunately nobile-type and phal-type Dendrobiums have distinctly different plant habits.

I found a good pic of a nobile-type showing both the blooms and a clear view of the stem with leaves in our own orchidgeeks archive.

I also found a good photo of a Dendrobium species used in phalenopsis-type hybrids, Den. biggibum. It shows the plant habit of this type of Den quite well.

You'll notice that the n