All the ways you've maintained even moisture in semi hydro... - Orchid Board

Plantcrazed101 · #1 10-20-2016, 09:28 AM

Hi y'all,

I'm curious as to all the ways you've maintained even moisture in the Semi-Hydro set up, and what you think of different methods so far, like placing Sphagnum moss on top, etc. I have a few types of plants that just don't appreciate that dry line, so I want to experiment to find the best way to keep the whole medium moist.

Also, has anyone use the water-holding crystals for the top of the pot? I just thought of that and was curious.

Ray · #2 10-20-2016, 09:39 AM

The best way is to elevate the relative humidity of the growing environment, as that is best for the plant. More humidity = slower evaporation = uniform moisture in the medium.

Dandrobium · #3 10-20-2016, 02:44 PM

I've been using a product called Synthic mixed in with the LECA which seems to help with wicking. I try to use it sparingly and oriented vertically to maintain the openness of the media. So far it seems to be working on my kovachii.
Also, I maintain 70%RH but I find keeping the semi hydro pots too close to the fans causes the surface to dry out too much. I use coarse LECA (Hydroton) so this effect seems pretty dramatic for me. A smaller grade of LECA may not be affected to the same degree.
I'm trying out using a bed of sphagnum an inch or so above the reservoir, then typical seedling media mix for some highland nepenthes. Still too early to tell how this will work out, but so far it is fairly even for moisture.

Plantcrazed101 · #4 10-22-2016, 10:03 AM

Great ideas! My reason for wanting to know other ways besides raising the humidity is because that's not always practical. For instance, I'd like to try Semi-Hydro outside, and with the wind and 100 degree temperatures, I really don't see any way that the moisture would wick all the way to the top, (or rather, even if it did, it would evaporate to quickly to stay moist) especially if that's not happening indoors at 70 F and 55% humidity.

Then my other reason is a recent test I did on two baby plants (not orchids). One plant had semi-hydro with enclosure so the humidity was high and the pellets stayed moist to the top, and the other had clay pellets with wet spaghnum at the top and no enclosure (so just 50% humidity or so). The one with the sphagnum at the top has outgrown the one with pebbles, even though all other conditions were the same, so I'm thinking that some very young plants will need wet or nearly wet conditions to get started, but I'd ultimately like to have mostly everything in semi-hydro because it's amazing...hence why I have to figure out how to keep a lot of moisture at the top if needed.

Ray · #5 10-22-2016, 02:26 PM

Quote:

Originally Posted by Plantcrazed101

Great ideas! My reason for wanting to know other ways besides raising the humidity is because that's not always practical. For instance, I'd like to try Semi-Hydro outside, and with the wind and 100 degree temperatures, I really don't see any way that the moisture would wick all the way to the top, (or rather, even if it did, it would evaporate to quickly to stay moist) especially if that's not happening indoors at 70 F and 55% humidity.

I think you are focusing entirely too much on what's going on it the pot. No matter how perfect the pot conditions, wind and 100 degree temperatures are going to desiccate the hell out of the plants!

MissRuby · #6 10-23-2016, 02:30 PM

I was having so much trouble last winter with this problem - purchasing a humidifier was hands down the BEST thing I ever did for my plants. I struggled with this all winter, here our humidity drops down below 30% - at one point in the house, it was down below 18! I couldn't keep up with it, and sphagnum and humidity trays did basically nothing. I purchased a basic cool mist humidifier, set it to the amount of humidity I want, and basically forget about it. Even now as the season changes from fall to winter, I've already noticed a drastic increase in the amount of times I have to refill the tank. All my semi hydro plants are thriving, pots are full of roots and I've noticed that roots at the top of the media are developing much better. I'm looking forward to better results this year!

Tindomul · #7 10-24-2016, 04:01 PM

That would be my solution, getting a humidifier. Only because I can add all the sphag or synthic I want and it would just dry just as much. Also, if you can sphagnum to the top, why not just place your plant deeper in the pot?
Having said that, I am currently growing seedlings of an Ericaceous plant in S/H pot on leca balls. The way I got the seedlings to sprout was to take live moss (sheet moss) and line one side of the pot, fill it with the leca, and then having excess sheet moss lie over the surface of the leca. The seedlings grew right on it. THe moss is alive and constantly moist so long as I mist it every 4 days or so. I usually mist it every day (Mon-Fri) but I know it can survive 4 days.

orchidudebcn · #8 03-03-2017, 08:33 PM

Hey everybody, John from Barcelona here. I was experiencing similar problems with a high evaporation rate and a dry line 1/3 way down the pot despite 2 humidifiers running 24/7. Sphagnum moss wasn't an option because, and I paraphrase Ray Barkalow, it will eventually break up and work it's way down the pot, blocking air passage and essentially clogging up the pot. So I decided to give Seramis a shot. There are 2 sizes of Seramis available on the market, large and small. I use the large, which ends up being around the same size as my leca pellets. I use a 2 to 1 leca to Seramis ratio in my pots, and it has significantly helped to maintain a more uniformly moist environment inside the pot.
PS - I can't believe no one distributes Seramis in the US...whoever finally decides to should do pretty well...seems like a hot commodity. If I still lived in New York I'd be all over it, lol, but I don't. So Ray, there's your cue, 🤣🤣😉👍🏼
Happy growing everyone! 🤓

estación seca · #9 03-04-2017, 01:18 AM

Ray was being kind. It's going to be impossible to maintain any kind of moisture level outside with 100 F / 38C temperatures and wind, no matter what is in the pot. If you potted the thing in a wet sponge sitting in a dish of 1" / 2.54cm of water it would be bone dry in an hour. S/H is not for growing outside in heat unless perhaps your reservoir is an inch from the top and you refill it every day.

MrHungx · #10 03-16-2017, 05:56 PM

I've always had problems with my cattleyas not adjusting to semi hydro because of the dry line. I originally started out with growing indoors, but increasing the relative humidity is not an option for me since I am sensitive to mold. I moved within the last year and can only grow most of my orchids outside. My temps range anywhere from 100+ Fahrenheit in the summer to the 20s in the winter. I initially used a top dressing of sphagnum moss to keep moisture in the pots, but am finding that they decompose too rapidly. I have also experimented with mixing Growstone with the LECA to improving wicking capabilities, but I am also experimenting with using Growstone as a top dressing instead of sphagnum.