Drier media

[benetay]

Hello all,

Just a brief introduction. In Hot Humid Singapore, what i can't achieve is the drying out process. Humidity maintains at 60-70% RH during the day and night. Hence, when i use Coconut husk chips, they tend to remain wet for a prolong period of time (e.g 1week or so). A lot of my plants took the toll before i had time to inspect them. Those that i manage to salvage are now potted in small rocks i bought from a local orchid nursery. (Something like limestone but in smaller pieces)

The stones do maintain a bit of moisture but certainly less then coconut chips and i top it off with a thin layer of Sphag moss. I recently added a new layer of perlite below the moss to further reduce moisture. Hence, i'm looking for something a little dryer. I heard that they ban the import of diatomite and i'm certainly left speechless. (what else is there to ban? gums for a start?)

What is a great dryer media that is closely related to diatomite? I'm having great trouble keeping them dry & rot do occur. I've tried charcoal, some how Bulbophyllum don't really like them.

Thanks in advance.

Cheers!

[Bolero]

Have you tried bark? I know it's not related to diatomite but it can be quite dry if you want it to be.

[benetay]

You mean cork bark as a potting media? Hmm i've never thought of that, all i have now are slabs of cork bark that i threw one side because they are too dry to mount any plants. Can i break those cork bark slabs into smaller chunks? Or is it better if i just buy cork bark chips?

Cheers!

[Bolero]

I meant more like pine bark chips rather than cork. I am not sure about cork but I use pine bark and if I want it to stay drier then it's very good for that.

[Ron]

Humidity maintains at 60-70% RH during the day and night. Hence, when i use Coconut husk chips, they tend to remain wet for a prolong period of time (e.g 1week or so)

Depends on what you are trying to grow.
My Phallies are in 12 to 18mm Coco nuggets and I need to water abot every 3to 4 days in summer.
Humidity is around 40 to 80% if I can maintain it.
It if was too wet for me I would rather go up to a bigger size, say 20 to 30 mm Co co nuggets rather than go back to bark.
What size Co co nuggets are you using.
Paphs are in 15mm bark and dry out in about 3 to 4 days in summer. too dry for my Phallies.
Best of luck
Ron

[benetay]

Originally Posted by Bolero

I meant more like pine bark chips rather than cork. I am not sure about cork but I use pine bark and if I want it to stay drier then it's very good for that.

Our pine bark isn't of great quality and they are almost similar to coconut husk chips

Originally Posted by Ron

Depends on what you are trying to grow.
My Phallies are in 12 to 18mm Coco nuggets and I need to water abot every 3to 4 days in summer.
Humidity is around 40 to 80% if I can maintain it.
It if was too wet for me I would rather go up to a bigger size, say 20 to 30 mm Co co nuggets rather than go back to bark.
What size Co co nuggets are you using.
Paphs are in 15mm bark and dry out in about 3 to 4 days in summer. too dry for my Phallies.
Best of luck
Ron

I'm using the bigger coconut husk chips (30-40mm) type and yet when i water, they never dry out since day one. I'm getting very worried for that. Sometimes the humidity goes right over the roof and comes way down. Something like 95% and 60% (tropics). There isn't much wind to go along with the high humidity causing it to remain wet for a long long time. It gets so wet that even the new bulbs, which are not touching the media rots off too & i have to snip it off.

I'm trying all sorts of media and hoping one day i can get it right but right now i'm still failing so.

Cheers!

[rcb]

Benetay - what about med size pieces of lava rock as the surface is more porous than regular rock. Lava rock is volcanic rock. Also, the other option is wine corks - as they are. I actually have a Rhynco gigantea potted in a net basket with wine corks and smooth stones. It takes a while to collect them but if you know any wine people, ask them to save them for you.

Also, if the stones you are using are holding less moisture than the coconut chips, why not use just them? Or is it too dry and you are looking to bring a little more moisture in?

[benetay]

The stones i'm using are seriously holding too little moisture as it's not as porous as lava rocks.

I'll try using wine cork & read up on lava rocks, i have huge ones but not for orchids.

Thanks a lot.

Cheers!

[Hummer344]

I would use larger chip although I do like the volcanic rock idea. Think I will get me some of that to use in my mix's

[benetay]

Thanks David, i'm not certain if i can get volcanic rock chips. Does bigger chip means more air circulation?

Cheers!

[rcb]

Benetay - when I'm using lava rock as my medium, I go through the bag and hand pick pieces based on size for the plant and pot combo. For example, if I'm using it in a regular pot, I use bigger pieces (size of a chicken egg), as it does not pack as well due to the irregular shape, and dries appropriately. If I'm using a net pot, which has more air flow through the pot, I use pieces about 1/2 the size of a chicken egg, they pack better and hold more water, but with the better air flow dry about the same. If I'm using in for a seedling or small plant, I use the smallest pieces about 1 - 2 cm diameter. It also depends on the overall size of the pot as well, bigger pots gets bigger pieces.

Does this help? If you want I can take a couple pixs to show.

BTW my goal with using lava rock, is on a sunny day, the plant holds water about 1/2 the day and dries by nightfall. I use it for my smaller Vandas, Angraceums. One reason i started using this rock was for plants that don't like to be repotted. Lava lasts a long time. But just be careful about amount of fertilizing. The lava rock doesn't rinse as well as other mediums.

Hummer - at one point I used it instead of styrofoam p'nuts in the bottom of my pots for my Catt alliance types. They loved it. But problem when I went to repot, the roots really loved it, and I couldn't get them off without cutting a lot of them. So this past summer I actually went back to using styrofoam peanuts.

[Ron]

I'm using the bigger coconut husk chips (30-40mm) type and yet when i water, they never dry out since day one.

perhaps you should look at what some of the big nurserys/growers are using.
I would have thought the 30 to 40 mm coco nuggets would do but I have never faced such humidity.
Best of luck
Ron

[Stelios]

Benetay i would like to suggest a synthetic medium. It is spongy, not decomposing at all, reusable and provides great air circulation. However you should always fertilize as it holds no nutrients. The name is epiweb and it comes in pieces, plates and custom (for orchidariums with pumps and pipes for watering).

Epiweb

[berniep]

G'Day Benetay

Isn't diatomite manufactured by treating it with liquid nitro glycerin, anyway I figure if you could work out the less harmful constitutes of "kitty litter" it would probably serve your needs. And I think you will find that may involve clay?
Just a thought but thought if you are going to experiment may help in the bottom of the pot.

Cheers
Bernie

[Ray]

1) Medium staying moist should really not be an issue if it's airy enough. Consider that orchids in nature - especially those from rain forests - can stay constantly wet for months at a time.

2) I don't know the availability in your part of the globe, but coarse LECA might be worth considering - dries more quickly than organic media components or diatomite, but holds more moisture than rocks.

3) My understanding is that diatomite is manufactured by calcining (firing) fresh water diatomic muds, then crushing and grading. The clay (Fuller's Earth") typically used in kitty litter usually are not fired, so the clay platelets can separate an form a really nice, suffocating slime!

[psyc1210]

I second using LECA if you need it to dry out a bit faster. Holds a good amount of moisture, and is cleaner

[maria1971]

I suggest LECA also. While I in no way live in an area as humid as yours, I live in Miami, Florida, where it's humid most of the year. I just transferred all my cattleyas, vandas and laelias into 100% hydroton, after trying most mixes (I grow outdoors) and lava rock. Lava rock was wayyyyyyyyyyy to dry, and everything else was wayyyyyyyyy too wet. LECA is perfect..I water, it dries, the roots love it, and most of all, it's readily available in large portions and I don't have to mail out for it.

Good luck.