Drying out Dendrobium, yellow leaves dry roots

[King_of_orchid_growing:)]

Looked at the pics.

That potting media needs to be changed out. It's degraded pretty badly. And yeah, it's bark, but it hardly recognizable as bark.

You can use medium grade bark or small grade bark (aka seedling grade bark)

Your Dendrobium is a NOID Dendrobium.

But...

It is what is generally called a Dendrobium phalaenopsis type hybrid. It is a hybrid where one of the parents involved in the cross is Dendrobium phalaenopsis.

Dendrobium phalaenopsis and kin are in the genus Dendrobium under the section Phalaenanthe.

Plants in the genus Dendrobium are often broken down into subdivisions of groupings called "sections" because of how large the genus is.

This particular hybrid does not experience a period of dormancy. It's "evergreen".

Eventhough it's deemed an "evergreen" Dendrobium, it doesn't mean that the leaves will not turn yellow and drop from old age.

[King_of_orchid_growing:)]

Originally Posted by Brandyb

I have the plant in a window facing Southeast.

I don't know how much light the plant is receiving by window direction. This is not the standard I use. I can't help you determine if this is adequate using this information.

Perhaps other members can.

Originally Posted by Brandyb

It is in a plastic pot that is set into my clay pot because I thought I shouldn't repot until blooming is finished.

See above post.

Originally Posted by Brandyb

The temps range from 65-70 degrees.

I'm assuming that this temperature range is due to the fact that your office building is air conditioned. Am I correct?

If so, this is part of the problem...

The temperature is too low. This is basically simulating night time temperatures all throughout the day for your Dendrobium.

Like I said, this temperature range is fine for it at night. But proper day time temperatures need to be at least 10 degrees F higher than the night time temperatures.

Here's the misconception about the temperature requirements for orchids. And I as a beginner had it too...

When people realize their plant is from the tropics. Automatically, people are thinking about steaming jungles or what not, with very constant temperatures.

I think the old time Victorian era orchid growers had this misconception as well, hence why so many orchids died under their care.

Anyways...

Well...

This is far from the truth. The tropics is actually very varied in ecological niches. It is not always a steaming hot house of a jungle in the tropics. Sometimes, it is very comfortable in certain places depending on where in the tropics you're talking about.

Temperatures are also not constant in the tropics. There is usually a noticeable difference between night and day temperatures.

Secondly, if your office building is air conditioned, the air is most likely not humid. Devices that measure humidity are actually not expensive. This would be a good investment for all orchid hobbyists.

Originally Posted by Brandyb

I have been watering when it is dry between one and two weeks between waterings...

This might not be enough water for your plant, idk. This would be in the context of how fast the potting media dries out and stays dry between waterings.

Originally Posted by Brandyb

...and fertilizing with Schultz Orchid Food. 19-31-17

While I've used this brand of orchid fertilizer before, there is a problem with this brand.

If you read the label, you'll quickly find that the type of nitrogen used is derived mostly from urea.

Urea is a very stable form of nitrogen. It will not breakdown unless there is soil with the proper microbes to start the breakdown process. If the urea does not break down, the plant is not able to use the nitrogen.

However...

A fertilizer utilizing nitrogen that is largely derived from ammonia or nitrate, will be available to the plant right away. This is what is called being bio-available.

You don't have to throw this fertilizer out. If you have other potted plants that grow in soil, they can use it just fine. Or if you've got Cymbidiums, it'll work too.

[Brandyb]

Is it okay to repot the plant now? or do I need to wait until the flower has fallen off?

The plant is in an office were the heat is set so that the nighttime temp is 65 and the daytime is around 70. It is not very humid, but I will work on getting a meter to check humidity as well as a light meter.

Thank you for the fertilizer advice as well. How should I decide when to water the plant? I was under the understanding that it should be completely dry between feedings... Is that incorrect?

[King_of_orchid_growing:)]

Fertilizing orchids should ideally be done once a week. But at a little less than the recommended dosage on the package.

Watering Dendrobiums should be done the following manner...

Water.

Wait until it dries out completely, then water again.

You're simulating rains.

If you see some of the pics of the Dendrobiums in the wild, the trees they're on are dry occasionally.

And it is fine to repot.

You can even repot even when the plant is in bloom!

Ideally if the potting medium is badly degraded like yours is, it's best to change it out regardless of whether it's in bloom or not.

If the plant dies you won't see flowers anymore, you gotta buy a new one. If the flowers die, but the plant lives, you'll see more flowers the next blooming season.

[King_of_orchid_growing:)]

Oh, yeah...

About some of my posts...

I recommend reading them over again. Sometimes while I'm typing, and after I post, I'll re-read them and amend the information or change the grammar, punctuation, or sentence structures.

Sometimes I even change the info.

[Brandyb]

Great! Thank you for all of your help! Hopefully I will be posting pictures of a happy and healthy plant in the near future.

[Movnhorses]

Holy smokes those are some pretty blooms on those wild orchids...

[flexdc]

Brandy,
Looks like your mix is staying too wet.
Can you pull it out of the plastic pot, see if all the roots are mushy and pot it into a smaller terracotta pot?
All dendrobium orchids like smaller pots, from the look of it yours is too big.

Your dendrobium likes high light a warm temps. 60 or above. A sunny west facing window is ideal.

Get some new bark (medium grade) and a 4 in pot (max size) and pot your plant in it. Pull out all the old mix and pot the plant in the new mix. Make sure it doesn't wobble. If it does stake it.

Let us know your progress.
Andrew