Semi-Hydro & Heat
 

I know that heat at the bottom helps when transferring to s/h. My question is how long do they need to have the bottom heat. I have some Cats where the new roots are already at the bottom of the container and very healthy looking. Can I move the plants to a sunny window yet or when?

Yes and no. For me, warm growing orchids stay on their mats because my environment its quite dry. Evaporative cooling can become a real issue. I'd say if you're in a warm place with humidity youll be fine.

I also live in Colorado. So probably need to stay on the heat. But I question the amount of light where my heat is. Pretty shady for Cats. Just west reflected light from my garage so not much sun at all. I guess I could move my heat source.

I do sell windowsill heat mats.... :)

Ray,
What sizes and how much?

Ray,
Never mind my question. I went to your website and found it. The size would be perfect for where I'd like to put them. Their not on an actual heat mat right now. About 6 months ago I realized that my flourscent light stand was putting heat on top of my stand so I had thought wow here's heat for the plants and it has been working. Does the heat mat turn on & off by itself or has to be done manually?

Heat mats stay on, but are such low wattage that they only boost the root zone temperature by about 10°-15°.

Don't confuse the applications.

When getting a plant established, you want the heat at the root system and not at the vegetation. Increased temperature equals more rapid metabolism, and by narrowing it to the roots, they get all the growth energy.

In the case of a dry environment, where evaporative cooling can push the root zone too cold (usually only an issue in winter, if you lower the thermostat), warming the entire environment to prevent that can work, as can a heat mat if you don't want to boost the thermostat.

So I believe the only difference from what I have now would just be the heat mat is always on. The heat now is at the root zone and very warm in that room also. My main question is once established can they go to a warm window without heat at the bottom. I won't leave them in the window when winter comes. Maybe I am not understanding.

Shawna I'd keep them on mats especially if you use a window for the plants. You'd be surprised how cold a window can get especially in our state. So unless you have fantastic windows, I wouldn't count on it being warm all the time. If the mat concerns you, you could always set it on a timer, too, so it's on just at night.

It all comes down to evaporative cooling. If your RH, temperature, and air movement results in significant evaporation of water from the medium, and, as Ryan states, your temperatures approach a point at which going lower could be damaging to the roots, then by all means, leave the heat on.

If we're talking phals, one of the more sensitive orchids to cold roots, I'd never let them get colder than 60°-65°.