How to keep orchids warm safely in winter?

[OrchidNut555]

I was wondering how to keep my orchids warm in winter without it costing me a fortune on electricity. i have heat mats but leaving them on whilst at work doesn't seem like the best idea. I'd hate for a warm growing cattleya's maturing pseudobulbd not to produce a flower due to the winter's annoying cold.

How do you guys keep your orchids warm in winter?

[Roberta]

I have an advantage in living in a (mostly) frost free area so I can grow most of my orchids outside all year. But... they are not warm. This time of year, night temperatures are 4-6 deg C (low 40's F) with occasional dips lower for a few hours. Of course, there was a combination of "intended selection" (I do try to choose cold-tolerant orchids), and where I have miscalculated, there's some natural selection going on too. But, there is a very large number of species and hybrids that do just fine. In selecting hybrids, do research the parentage. Many of the Cattleya species in the background of these hybrids are quite cold tolerant. There are a few, like C. dowiana and C. lueddemanniana, that really do need to be kept warmer, hybrids where they are dominant also. Most of the intermediate-sized and mini Catts are very forgiving. One note... if plants are cold, they need less water and fertilizer. Let them get rather dry, water only in the morning so that they are dry by nightfall.

For your heat mats, perhaps a timer, so that you can leave them on for a few hours while you're at work but not for the whole time. Seedlings do need a bit more tender loving care than mature plants.

[Dalachin]

If you mean seedling heat mats, I leave those on all the time in the winter, except for a few which are on timers to go off with the grow lights at night (for orchids that like the change in temperature). I have them on every windowsill where orchids are growing. I live in central ny, my orchids suffered before I got them. For the real warm growing species, I have a clear plastic tent around my grow shelves to trap the heat from the mats and the lights.

[PuiPuiMolcar]

I put Christmas lights chain around my Catts, for ones that are in spikes I put them in a big box at night with the light. If there's any thing I learn about growing orchid here, it's easier to keep plant cool than it is to keep them warm. Most catt I grow outside dont mind the cold, but it is the draft of cold air that's dangerous.

[Paphluvr]

Originally Posted by OrchidNut555

I was wondering how to keep my orchids warm in winter without it costing me a fortune on electricity. i have heat mats but leaving them on whilst at work doesn't seem like the best idea. I'd hate for a warm growing cattleya's maturing pseudobulbd not to produce a flower due to the winter's annoying cold.

How do you guys keep your orchids warm in winter?

I assume that you are an indoor grower? What types of orchids are you growing and what are your conditions? I, myself, am an indoor grower and the orchids I grow enjoy the same indoor temperatures as I do. Winter night temperature is around 16*C and daytime temps around 21*C. For your Cattleya, nighttime temperatures could be colder.

[Ray]

There are actually two issues (besides the cost of energy), providing the heat and holding onto it.

Lots of things can provide heat - seedling mats, heaters, lights, even fan motors - but just like water evaporating from a tray, the trick is confining it so it won’t get dispersed throughout the living area, where it will have a minuscule effect.

“Tenting” the plants with plastic sheet will trap the humidity and heat, but using some foam panels to “box” them will be even more effective.

I had an unheated basement in Pennsylvania. I built a “seedling nursery/intensive care unit” starting with a 1 x 2 meter plastic hydroponics ebb-&-flow table to which I added sides and a top made from 5 cm polystyrene insulation sheets. I fabricated sliding glass windows for the front for access.

It was illuminated by two Phillips commercial 35W horticultural LED strips, there were two “muffin fans” for air circulation, and there were two 15W seedling heat mats. In a 55F (12-13C) basement, when all were on, the chamber got into the upper-80’s (30-32C) if not higher. Overnight, the heat mats alone would maintain it at about 75F/24C, so unless I was trying to encourage rerooting, I cut back to only one mat to drop the temperature a bit.