This unit lasted many years, long after we officially closed the retail plant sales side of the business.
When I owned my own greenhouse, I started everything myself the first year, getting seeds from seed purveyors, and cuttings from whoever would give them to me. I had to work that way since I had no money. I started my greenhouse business with only $700, and with this money I needed to get everything — including the structure (I built a solar greenhouse). I had to innovate. One way I saved was to build my own propagation tent. I couldn’t afford to buy one and even one of those mats was out of reach. Here’s how I did it.
Tent Placement
I had built wooden benches with hardware cloth as a covering. The cloth (which is metal mesh with roughly 3/8-inch openings) allowed water to drain and air to circulate. From the main bench, I had peninsula benches extending from the main trunk. I chose the last one located at the end of the greenhouse by the exhaust vent so it’d be out of the way and less subject to damage. Moreover, it was a double decker bench (fig. 1). Since I needed to shade the tent so it wouldn’t overheat, the upper level would well serve said purpose. This location was ideal.
Basic Construction
I had three goals in mind, besides it being large enough to accommodate my small operation’s needs: It had to contain heat and moisture, it had to keep out direct sunlight, and it had to operate economically. To meet these requirements I figured I’d need and under-over construction. The lower part would contain the heat source — a 100 watt light bulb — and the upper part would be the actual tent. For materials I had a half sheet of old plywood, some aluminum foil, a bit of scrap wood, some white poly sheeting, an adjustable light fixture that I found at our local recycling center, and a handful of screws. I started with the plywood cutting it diagonally to create two large triangles (fig. 2).
I then bisected them the same way so I ended up with four triangles. (I could have used just two triangles, but the construction of the bench frame demanded I make the second cut.) I attached these triangles to the bench (fig. 3) as left and right uppers for the actual tent area, and left and right lowers for heat source containment. I applied a cut-to-fit scrap piece of plywood between the lower triangles forming an upside-down lean-to of sorts when viewed from the front. I then attached the white poly between the upper triangles forming an right-side-up lean-to of sorts when viewed from the front. I also lined the insides of the upper triangles with poly to allow more reflected, filtered light inside the tent. I added aluminum foil to the lower surfaces to better contain the heat. I attached the poly and foil with a staple gun.
Heat Box
I attached an adjustable fixture inside the lower section. It had a small clip and I just clipped it onto the lower shelf’s hardware cloth (fig. 4). I was very careful with this to ensure the 100 watt light bulb I was going to install wasn’t going to get wet, it wasn’t going to come too close to the plywood or upper surface (didn’t want to burn down my greenhouse), and that it wasn’t going to come loose and reposition itself. Once I was satisfied, it was time to add aluminum foil to the lower shelf hardware cloth above the heat box and it’s light bulb. This would prevent the transmission of light into the upper tent area, and it would prevent water dripping down from above. The trays I was going to use were not the draining type, but I didn’t want to take chances with mist. Once everything was good to go I attached a piece of foil lined wood to the open face. I used right angle hooks that I could turn away allowing easy removal and access to the space to accommodate light bulb changes.
Propagation Tent
The last step was to form the tent. This was just about done already. The sides (upper triangles) were in place already and covered with white poly, and there was white poly already stretched across top to allow some filtered light inside. I just needed to add a front curtain made of white poly, split. I added a few split shot fishing sinkers to the bottom edge of these “curtains” to weigh them down and make a better seal (fig. 5).
The Outcome
That’s it. I kept the light bulb on which provided an excellent source of heat. By way of radiation (and some convection and conduction, too), it made the moistened vermiculite I rooted my cuttings in nice and warm as was the air in the tent. I also misted quite a bit. Between the diffused light, warmth, and high humidity, this unit proved itself very worthy. A regular cuttings machine! I later installed a hose-end mist tube in my greenhouse and snaked one of the emitters inside the tent to automate the operation to a degree.
This unit lasted many years, long after we officially closed the retail plant sales side of the business. It rooted perhaps 1000s of cuttings, many of which where plants that were “difficult to root.” The operating costs consisted of the cost of keeping a 100 watt bulb burning which was seemingly reasonable. At the time there was a definite lack of funds (there was time and sweat aplenty, though), so this elaborate set-up ended up saving precious start-up capital. If a heat mat was within reach at the time, the entire lower section could have been omitted, but I did what I had to do.
