Winter blues (coping with cold & dry conditions)

[estación seca]

I have grown cactus indoors under T8 fluorescent lights in a cold-winter climate, but not orchids.

You haven't mentioned temperatures. Also, if I read you right, your plants are getting almost 24 hours of light? You have the lights on at night and the plants are near a window? Most of our orchids are tropical, and they aren't adapted to very long days.

Your humidity 30%-60% is adequate and will not cause severe problems. But cold and dark will.

I might recommend turning the lights on before dawn, and off after dark, so the plants get around 10 hours of light. Turning them on during the day lets them supplement the natural light, so the peak light intensity will be greater than it is now.

What is your temperature range? This is very important for wintering orchids.

[greenpassion]

Originally Posted by estación seca

I have grown cactus indoors under T8 fluorescent lights in a cold-winter climate, but not orchids.

You haven't mentioned temperatures. Also, if I read you right, your plants are getting almost 24 hours of light? You have the lights on at night and the plants are near a window? Most of our orchids are tropical, and they aren't adapted to very long days.

Your humidity 30%-60% is adequate and will not cause severe problems. But cold and dark will.

I might recommend turning the lights on before dawn, and off after dark, so the plants get around 10 hours of light. Turning them on during the day lets them supplement the natural light, so the peak light intensity will be greater than it is now.

What is your temperature range? This is very important for wintering orchids.

I don't grow catts, mainly phals and dens. I have all my phalaenopsis orchids that are under lights on a timer. I've had it set up this way for years. 14 hours on. I also have my pre-mixed gallon water jugs on a shelf underneath, and the jugs are on a heat mat strip. So the water that I use for them is always a nice warm temp.

[SundayGardener]

Originally Posted by estación seca

I have grown cactus indoors under T8 fluorescent lights in a cold-winter climate, but not orchids.

You haven't mentioned temperatures. Also, if I read you right, your plants are getting almost 24 hours of light? You have the lights on at night and the plants are near a window? Most of our orchids are tropical, and they aren't adapted to very long days.

Your humidity 30%-60% is adequate and will not cause severe problems. But cold and dark will.

I might recommend turning the lights on before dawn, and off after dark, so the plants get around 10 hours of light. Turning them on during the day lets them supplement the natural light, so the peak light intensity will be greater than it is now.

What is your temperature range? This is very important for wintering orchids.

Not sure if this is intended for me...I have T5HO and we turn them on at dawn, then off after the sun rises. The plants are in a protected southern exposure. Then the lights go back on in the evening and off at bedtime. House temp varies between 65 and 75 F, it's steam heat and hard to regulate. When it is below freezing outside, the indoor temps go up, but when it is mild outside, it gets cooler indoors. With plastic now draping the shelf, we moved the lights about 4" further away from the plants. Leaf color seems OK to me, not too dark, not too light. I'm more obsessed with the roots and I do tend to over water which is more of a problem in the winter when things do not dry out as quickly. I have a bad track record with phals and rot which is probably why I focus on roots now. I'm not sure that they are getting enough air movement.

Of them all, the encyclias look really happy. The catts are more of a challenge, I know the roots don't like to stay wet, but the new root tips were browning so I now mist them and hope the increased humidity will also help.

[Paul]

Unless your catt leaves are chartreuse or showing burn marks, there is no reason to move the lights further away from them. I have bloomed many a minicatt under fluorescent tubes and generally have the leaves within an inch or two of the lights.

I gave up the winter humidity battle long ago. My winter RH is generally around 10-15%. Running a humidifier 24/7 would sometimes get me up to 30% but that was it. I surmised that lack of good insulation common to apts was likely the problem but there was nothing to be done about that.

You might try watering with one of those pump sprayers + wand which are commonly used for pesticide application. It would enable you to moisten the surface of the media with some trickling down deeper but avoiding a thorough soaking.

[estación seca]

Sorry, I misunderstood your lighting. If you have hidden mealybugs you didn't kill, that could lead to sick Cattleyas.