Potting media for people who like to water

[Ray]

Originally Posted by wintergirl

For some plants I add styrofoam pieces and marbles to my bark mix, especially in the bottom to help drainage.

Want to hear something funny? Adding a "drainage layer" can, in some circumstances, lead to a wetter medium!

We want the potting medium components to absorb moisture, but we absolutely don't want water to occupy a substantial amount of the free space between particles, as that suffocates the roots.

That water is held in place by surface tension, and if you have a relatively tall column of potting medium, the mass of the water overcomes that holding ability to a certain degree, and gravity literally pushes it out the bottom. It may still be relatively sturated at the bottom, but the top part of the medium ends up drier.

Put a "drainage layer" in the same pot, and the height of the medium is reduced, meaning there is less water mass to overcome the surface tension, so the medium actually stays more saturated.

[wintergirl]

Originally Posted by Ray

Want to hear something funny? Adding a "drainage layer" can, in some circumstances, lead to a wetter medium!

We want the potting medium components to absorb moisture, but we absolutely don't want water to occupy a substantial amount of the free space between particles, as that suffocates the roots.

That water is held in place by surface tension, and if you have a relatively tall column of potting medium, the mass of the water overcomes that holding ability to a certain degree, and gravity literally pushes it out the bottom. It may still be relatively sturated at the bottom, but the top part of the medium ends up drier.

Put a "drainage layer" in the same pot, and the height of the medium is reduced, meaning there is less water mass to overcome the surface tension, so the medium actually stays more saturated.

Interesting. I don't do it in all my pots just in some. It's not really "a layer" it's scattered. So far things have been great. I guess time will tell if I continue....

[MNBloom]

I buy "Biochar" and have had good success adding it to my potting mixes. From this company:

Biochar and Gardening

I buy a 15 lb bag but I use it for my cactus mixes as well in the greenhouse. A little goes a long ways...

[ChipMolly]

I tend to overwater myself. Like everyone else I aim for high porosity potting mixtures, but I'm transitioning to mounts now which i can water to my heart's content and they're still fine, as long as you don't mount with sphagnum moss (or use less depending on your watering regime).

[oscar freak]

i found some chopsticks and inserted them in all the pots,the plan was to water tomorrow which would be 11 days since the last watering,had a quick test and they all came out cool and damp.will do daily tests till their not.who knew bark could stay wet so long

[The Mutant]

Hi, notorious overwaterer here.

Despite being so happy with the watering-pot I still use mainly bark in my substrate. What I try to avoid is fine particles so I always rinse the bark from dust etc and also too decomposed pieces. I also try to keep the bark pieces 'chunky' and adapt the rest of the mix to the individual plants.

I'm in the middle of repotting my entire Paph collection and have noticed which media they don't seem to appreciate and which they do. So for some, I now use straight bark (only a top layer of sphagnum, for root growth encouragement and because otherwise they dry out so unevenly and fast), others get my bark/sphagnum/perlite mix, some with crushed marble in and others with some packing peanuts added. All depending how the roots have previously grown and what they look like now.

I probably use coarser bark pieces to the Paphs than most do and that's because I water too much. So, since I apparently can't stay far enough away with the watering-pot, I'll have to change something else. It seems to have worked with the Paphs I have left (some I'm nursing back from previous killing attempts).

Question: can't you bring your orchids indoors during the worst storms so they don't get too much water? Or am I missing something...

Originally Posted by Ray

Want to hear something funny? Adding a "drainage layer" can, in some circumstances, lead to a wetter medium!

We want the potting medium components to absorb moisture, but we absolutely don't want water to occupy a substantial amount of the free space between particles, as that suffocates the roots.

That water is held in place by surface tension, and if you have a relatively tall column of potting medium, the mass of the water overcomes that holding ability to a certain degree, and gravity literally pushes it out the bottom. It may still be relatively sturated at the bottom, but the top part of the medium ends up drier.

Put a "drainage layer" in the same pot, and the height of the medium is reduced, meaning there is less water mass to overcome the surface tension, so the medium actually stays more saturated.

Interesting... I didn't know this either. I add packing peanuts (Styrofoam) into the mixes of some plants that like a lot of airmovement around the roots and/or not stay wet for too long. I have a Paph parishii that I have a layer of packing peanuts in the bottom of the pot of. I'll keep an extra eye on how long the bottom layer stays moist. Thanks for sharing the information.

[oscar freak]

Question: can't you bring your orchids indoors during the worst storms so they don't get too much water? Or am I missing something...

Thats the problem they are away from the storms on the verandah,i want to pot them so they can enjoy the storms without becoming waterlogged.

[Jenn4a]

Originally Posted by oscar freak

i'v been searching high and low for agricultural charcoal with no luck...

I'm not sure if you got an answer for where you can purchase charcoal, but if you use amazon you can try this. Hoffman 17502 Charcoal Soil Conditioner, 24-Ounce https://www.amazon.com/dp/B001ACPZ0W..._BAySub0G7H80Z
There's other charcoal products available, but I have the charcoal I linked. 10$ for 24 oz and free 2 day shipping with prime, I haven't tried it yet though. I think it's about a medium grade or between fine and medium?

[cbuchman]

When there is a big storm coming, I have a party tent that is about 12 feet x 12 feet which I can put up over my outdoor growing space.

Pots still get wet - it's amazing how much water splashes off my patio cement deck and hits the benches on which the orchids sit. however, they get drowned, so it works for me.

I leave the tent frame up all summer and just put up the tent part when there is a heavy storm or multiple days of rain expected.

[Leafmite]

We get the big storms and, some years, weeks on end of rain. I wouldn't say that I love watering but I do admit, I cannot gauge whether orchids need water, unlike with my other plants. In the beginning of my growing career, I tried the large bark but I quickly moved on to red lava rock and basket pots. It has made things SOOOO easy. In the summer, it can rain for three weeks straight and I just laugh and tell the orchids that it is monsoon season. If temperatures turn cool just after I have drenched the orchids, I don't need to worry about trying to dry the medium before the roots rot.
Now that I am collecting smaller orchids and have a few orchids that need more moisture, I have begun using LECA, the little clay balls, as medium. They still allow great drainage and don't decay (which causes bark to hold more water) but they are closer together so they hold a little more humidity for the smaller orchids. The large Dendrobium I acquired this November, however, went directly into red lava rock.
I have grown Paphs, Phals, Cattleyas, Oncidiums, Dendrobiums and even my Max. Ten. in red lava rock with success. The medium is cheap, lasts forever and, in a basket pot, can easily be flushed.
When using red lava rock or LECA, I have found that less nitrates and more Calcium seems to work better. I also add the occasional Epsom salts and put a little Ironite in the watering can to slowly dissolve as the rock doesn't really hold these sorts of nutrients very well.

I have had a few of my orchids in the same red lava rock for eight or nine years. I did originally have them in clay pots and basically just transferred the entire mass of each orchid from the clay pots to the basket pots.