D. Aggregatum questions- winter rest and others

[Fishkeeper]

I found a D. Aggregatum at Lowe's today, and, after some quick Googling on my phone, decided to give it a try. So, I'm here with questions.

First off, how do I tell if it's getting enough light?

Second, it has a grower's tag with it that says:
21656 Dendrobium
Aggregatum- Thailand
Specie- 11/13/12
I assume this is an ID code, the origin of the variety, and the date it was planted. Am I correct?

Third, and most important, I've been reading about the winter rest that they require, where you just about stop watering the plant. If I don't do that, will the plant die, or will it just not get the signal to flower?

And are there any other tips?

EDIT:
Additional question. I've just gently de-potted it to take a look, and it's not terribly happy at the moment. I couldn't see the roots because of how it was packaged, so I went by leaf health, which is great. The rest of the plant is a bit unhappy.

There are at least a dozen pseudobulbs, ranging from 1" to 1/3" tall, and they all have leaves that appear healthy. However, the pseudobulbs are badly shriveled, so badly that they're ridged.
I haven't cleaned the root ball off to check on all the roots, but some are kind of dull brown and haven't greened up in water. The plant appears to have some good, healthy roots, though, I think it just hasn't been watered enough. Or, possibly, the usual "spray all the orchids with the hose" treatment just wasn't enough water at the time because of how it's potted.

The substrate is mostly charcoal and perlite with some big chunks of fir bark, which I think is a fine substrate for this type of orchid, but it probably just couldn't hold enough water from the spraying everything usually gets.

I want to get this plant re-hydrated, but I'm not sure how to do that safely- any advice? I've poured water through the pot a few times to help moisten everything up, and I'm leaving the pot soaking in water for about 20 minutes. I assume this will put as much water into the bark as the bark can hold, which seems like a good thing at the moment.

How long should it take, with regular watering, for the pseudobulbs to plump back up and be healthy? Should I water more often while re-hydrating the plant?

Also, could I grow this plant in pure charcoal and pumice? I'm working on a setup, a miniature living wall, that I want to contain as little organic substrate as possible to help prevent fungus gnats.

[voyager]

One would need to be able to read the mind of the grower to decipher the tag fully and completely.
But, the #'s in the 1st two lines are probably a batch number for the germination group with the species name following, then the location of the seed source.
Then, I interpret the final line as defining the plant as a species plant followed by the date germination was begun.
And, I could be off in La-La Land too.


Den aggragatum's appearance makes it look like a plant that has to survive long dry periods.
Its single leaf is thick and hard.
Its PB is short, thick and also very hard.
It look and feels as if it built to withstand water loss. The PBs do shrivel as they age and will also shrivel when they are deprived of water.
They do need to be moderately deprived of water in the cool-dry-winter rest.
My experience with them is that they will never re-inflate to what they were before being water deprived. Throw a few spines on it and it could look like a cactus.

Most cultural info I've seen for this plant implies high light levels with a severe dry rest and very cool winter temps.
I tried that while trying to grow this in home in AK.
I could never get it to bloom.
Possibly the short winter days were the reason.

I have one her in HI growing mounted on a palm tree.
It gets a lot of direct sun on clear days.
We have been experiencing winter droughts but get morning dew every day.
Winter temps have never gone below 56°F.

It has been blooming regularly.
But I think it is not completely happy and could do better - maybe a bit cooler temps - maybe a bit more light. I think it is happy with the rainfall and dew it gets here.

When I grew it in home I used a mix of pumice stone[3/8"-] and chopped NZ moss in a 60/40 ratio. It grew very well in that and seemed to like it.

[Leafmite]

Good luck with your new orchid!

[King_of_orchid_growing:)]

Firstly, Dendrobium aggregatum is now a synonym for Dendrobium lindleyi. It is in the section Densiflora.

Originally Posted by Fishkeeper

First off, how do I tell if it's getting enough light?

The leaves should not be too dark a green. This species grows in pretty bright indirect light. Think Cattleya bright or even Vanda bright.

Originally Posted by Fishkeeper

Second, it has a grower's tag with it that says:
21656 Dendrobium
Aggregatum- Thailand
Specie- 11/13/12
I assume this is an ID code, the origin of the variety, and the date it was planted. Am I correct?

As was mentioned, it is difficult to know for sure what everything on the tag means, but I will pretty much agree with voyager.

The numbers, 21656, are most likely a product code of some sort.

Obviously, Dendrobium aggregatum is the species name.

Thailand is most likely either the origin of where the plant was produced or shipped from, or it could be one of the locations where the plant is naturally distributed in the wild.

Specie, is indicating that this is a species.

The date, 11/13/2012, could be the date the seeds were probably sown. This does sound about right. Will tell you why later...

Originally Posted by Fishkeeper

Third, and most important, I've been reading about the winter rest that they require, where you just about stop watering the plant. If I don't do that, will the plant die, or will it just not get the signal to flower?

They must get a winter rest. It is not just a matter of flowering, it can sometimes be a matter of their health. Do not ignore winter rest for this group of orchids.

Watering has to be on the sparing side during the winter. Once every 1.5 weeks to 2 weeks is good enough of a dry spell.

In my opinion, this is a good species to practice dormancies with. Other species may not be as forgiving for providing an adequate dormancy.

Originally Posted by Fishkeeper

There are at least a dozen pseudobulbs, ranging from 1" to 1/3" tall, and they all have leaves that appear healthy.

The sizes you indicated tells me this is a large seedling. It will probably bloom next year if you grow it right. If not, then the following year.

I would consider your orchid near blooming size (NBS).

This is one of the reasons why I believe 11/13/2012 could be the date the seeds were sown. The other reason is that November is dormancy period. The seeds probably didn't germinate until either February 2012 or March 2012. Third reason is that if it took 3 years to grow in flask to become a seedling that is large enough to deflask, and it took another 2 years for the deflasked seedlings to get to the sizes you mentioned, that would make a lot of sense.

If 11/13/2012 were the deflask date, your plant would most likely be larger than what you described it to be.

Originally Posted by Fishkeeper

However, the pseudobulbs are badly shriveled, so badly that they're ridged.

For this species the pseudobulbs being ridged is normal, especially after dormancy. Just make sure it is not too shriveled. Without a photo, it is difficult to say how dehydrated your plant is if it even is dehydrated at all.

Originally Posted by Fishkeeper

I haven't cleaned the root ball off to check on all the roots, but some are kind of dull brown and haven't greened up in water.

Sounds like the roots might be dead. Gently pull on the roots to see if the velamen comes off.

It is normal for some of the roots to die during dormancy.

Originally Posted by Fishkeeper

The plant appears to have some good, healthy roots, though, I think it just hasn't been watered enough. Or, possibly, the usual "spray all the orchids with the hose" treatment just wasn't enough water at the time because of how it's potted.

Be careful not to overwater. If you are not familiar with how to grow it, do not water it too much first. You might think that it is dehydrated because of the ridges on the pseudobulbs, but it might be ok. It is best to post pics to be a bit more certain of this.

Originally Posted by Fishkeeper

The substrate is mostly charcoal and perlite with some big chunks of fir bark, which I think is a fine substrate for this type of orchid, but it probably just couldn't hold enough water from the spraying everything usually gets.

The potting media is fine for this group of orchids. They like the potting media to be airy.

I tend to disagree with you on the second portion of your sentence. I think it may be quite enough for the orchid's needs. Again, it is best to post photos.

Originally Posted by Fishkeeper

I want to get this plant re-hydrated, but I'm not sure how to do that safely- any advice?

Water when dry.

Originally Posted by Fishkeeper

I've poured water through the pot a few times to help moisten everything up, and I'm leaving the pot soaking in water for about 20 minutes.

I don't recommend making soaking the plant in water for 20 minutes every time you water a regular thing. When I say I don't recommend it, I mean, I strongly don't recommend it.

Originally Posted by Fishkeeper

I assume this will put as much water into the bark as the bark can hold, which seems like a good thing at the moment.

It doesn't take too much for bark to become saturated with water over time. The more broken down the bark, the more water it is likely to retain.

Originally Posted by Fishkeeper

How long should it take, with regular watering, for the pseudobulbs to plump back up and be healthy?

Without seeing the plant, I can only assume that you may be worried about the plant being dehydrated when it may really not be. I don't think the older pseudobulbs will plump up to be smooth again.

Originally Posted by Fishkeeper

Should I water more often while re-hydrating the plant?

Be very careful with a species like this...

It may like quite a bit of moisture during growing season, but it can still be overwatered and it can still rot.

It is more difficult to overwater if it is grown like how Leafmite had it, (in a basket with bark). In a pot, you might not want to get overzealous with water.

Originally Posted by Fishkeeper

Also, could I grow this plant in pure charcoal and pumice?

I don't see why not.

Originally Posted by Fishkeeper

I'm working on a setup, a miniature living wall, that I want to contain as little organic substrate as possible to help prevent fungus gnats.

Cool. But as an fyi, I don't think it is likely you'll get fungus gnats with large grade bark. You're more likely to get it from any plants grown in moss or potting soil. The caveat being that if the bark is staying wet all the time, (which you shouldn't be doing with this orchid to begin with).

You might be aware of it already, but I'll say it anyways, charcoal is considered organic material.

[voyager]

In response to your concern about rehydrating the PBs.
This is what the plant will look like:

Note the new growth coming from the base of the middle PB in the top row.
When in their first season's new growth they will be round and smooth. After the first season's growth and going into their first cool-dry-winter's rest, they will end up looking like the balance of older PBs.
You will never make them look like a young PB again. Just as I will never look like a 16 y/o again.

One other point I've noticed about this one. They grow better on a horizontal surface than a vertical one, especially as the plant gets larger.

[Fishkeeper]

Wow, lots of info, thanks!



Here's some pics of it. I looked up some pics of healthy individuals, and this one is way more ribbed than they are, plus the ribbing is deeper on some parts of the bulbs than others and the bulbs are nearly flat. Lighting in the pics is bad, the leaves aren't as dark as they look here.

I definitely won't be soaking it every time to water, that was a one-time thing to give it a big drink.

I'm thinking about tucking it against a wall made mostly of Great Stuff foam, with some substrate under the roots to retain a bit of moisture, supported by some driftwood. This setup will involve Hygrolon mesh, but I'll keep that away from this guy.

I know charcoal is organic, but I've never heard of people having problems with fungus gnats breeding in charcoal. I could be wrong on that, though.

[King_of_orchid_growing:)]

Prior to purchase, the plant did not get enough light for sure.

Believe it or not, your plants are not as dehydrated as you think they are. They could use a little bit more water temporarily, but, to me, and maybe even to other people who know, I wouldn't be terribly concerned about your plant the way it is. It is, for the most part, fine.

You're probably just not used to an orchid that naturally looks like this.

The "rectangular" shaped pseudobulbs are fairly young. Mature pseudobulbs will have ridges. Some orchids behave like this, and this is normal.

You seem to have a new growth going on with the plant. For now, observe how that new growth behaves and you will understand what me and voyager are telling you.

[Bluesky]

These plants in my opinion DO NO like to be re potted.

[estación seca]

Cool winters are probably much more important than withholding water for good flowering. Growing in the house or greenhouse may not provide cool enough winter days and nights for good flowering. This group of species gets down into the low 40s F / 4-6C every night in winter, and is also wet with dew almost every night in the winter.

During the summer species in this group are water hogs, but their roots will rot if stuffed into airless media. The best ones I have seen were grown as mounts, in humid warm summer environments, watered every day.

I had a tiny D. lindleyi seedling on a mount. It grew really well when I had time to submerge the mount in water every night and remove it the next morning. It died when I was away from home for a week and it fell out of range of the mister nozzle.

[tellmewhy]

My Den.Aggregatum also got from Lowes. I did not give it any winter rest and it bloom twice this year for me.
My growing condition.
Summer growing out door until the night temperature drop down to 40F. Full sun in the morning and water everyday. Fertilizer weekly with 1/4 tsp MSU.
In the winter, I water when the moss is dry out. No dry rest.HTH!