How to use a heating cable

I acquired several long heating cables at a 90% off sale, but don't have a clue how to use them. Mine are quite long (48 feet long). I have read they should be place inside a sand bed, with the rooting medium above them.

I imagined using separate small pots, so that the various cuttings could be removed easily when the root, rather that using one large open flat. Does that mean I can't use the heating coil?

48 feets sounds too long for even a regular-sized flat. What is the ideal use for this kind of coil?

Can they be used under a flat, the way a heating mat would be used?

Thanks!

LOL! I had a heating cable once and I taped it to the bottom of the cement floor where I had the bright idea to start seeds. I just went up and back and up and back over and over and taped it. The whole idea was dumb from start to finish. The cold cement floor was too drafty for seedlings, the tape didn't hold, and I couldn't slide my trays over the cable.

This doesn't mean your 90% off cable was a bad investment and won't work...this means than I wasn't able to make it work for me, and then I lost it, or put it away in a special place where I would be sure to find it, and never did. :))

Suzy

Sigh. Mine have been in a "special place" for several years, and I just bumped into them yesterday when I was poking through my propagating supplies. The few dollars I spent on them may have been folly -- seemed like such a good buy at the time.

I made a heat box for starting seeds, cuttings, etc. by taking one of the large, shallow plastic boxes you use to store things under the bed and coiling a 12 ft. long rope light around on the bottom of the box. I then put 2-3 inches of sand over the coil of rope lights. I plugged the lights into a dimmer switch made for lamps that I bought at Lowe's, I think, so that I could regulate the temperature of the box by making the lights dimmer, brighter, etc.. I just set my flats of seeds and small pots of seedlings on top of the sand to keep them warm. I suspended 2 shop lights with sunshine bulbs over the sand box to provide light for the seedlings, etc. It has worked quite well and I have been very pleased with it so far. I realize 48 ft. is a lot longer, but perhaps you could build a large wooden box or tray for the sand and coil your heat cable in the bottom of it and use a dimmer switch to regulate the temperature of the sand. Sounds like a very good and useful buy.

Cathy

Thanks, Cathy. I think I would find that large a box unmanageable, since cleaning the whole thing out would require removing everything growing it in. When I bought the cables, I assumed they would go under a box, the same way a heating mat does.

I don't plant anything in the box. The sand is used to absorb the heat from the rope lights and distribute it more evenly. I plant the seeds, cuttings, etc. in the same seed flats and small pots I always have, and simply place them on top of the warm sand which transfers the heat to the seed mix, potting soil, etc. that I am actually growing the plants in. I can add or remove plants at any time or rearrange them to change the amount of light they receive. The sand remains clean and is not affected by the plants. I suppose I will remove the sand and clean the box eventually when it is not in use, and probably sterilize the sand or change it for new sand just to be safe, but the warm sand serves the same purpose as a heat mat and is totally reusable and the temperature is adjustable.

By the way, I think many heat cables are also designed to be buried in the soil in your garden to warm the soil and extend your growing season. You might want to research whether the cables you bought are approved for outdoor use in this manner.

Cathy

Aha! I had no idea -- that is a huge help.