Every indoor plant enthusiast can recall being tempted into trying one of the many house plants requiring greenhouse conditions, only to find that no care can prevent rather sudden death.
For many who own their homes, a greenhouse is an eventual answer. Greenhouses today can be fitted into almost anyone’s budget.
Greenhouse gardening, however, is no respecter of persons. Those beautiful exotics sprinkled through the pages of house plant catalogs are as tempting to the third-floor apartment dweller as to the homeowner in the suburb.
But a greenhouse is out for an apartment dweller and countless gardeners like him who rent their homes, no matter how inexpensive.
My wife and I found ourselves in this situation. We knew we would be moving several times before finding a permanent location.
Pressed by a rapidly growing bromeliad collection that was beginning to include species intolerant of living room conditions, we looked for a solution.
We found it in an old used display case found in drug and department stores.
With it, we have been able to approximate greenhouse conditions and have been busy raising many of the plants which formerly gave us so much trouble.
Big Enough For Large Plants
While it might seem like an oversized terrarium, the display case has two distinct advantages. The most important, of course, is size.
Plants rarely become so big they look out of place. And much bigger plants can be grown than would fit into the average terrarium.
Another advantage is the ease with which temperature can be controlled. In our 6-foot case, full morning sun rarely raises temperatures above 90° degrees Fahrenheit.
The sun would burn plants in a terrarium because of the limited air volume.
Converting a display case into a “greenhouse” is a simple, inexpensive job. A used case can probably be bought for under $20, less than the glass would cost new.
Most cases average about 6 by 3′ feet by 4′ feet high, but exceptions exist.
With a little watching of want ads, you should be able to find one to fit your needs.
You can begin sampling a few of the more difficult plants by adding fluorescent lights and a waterproof bottom.
Fluorescent Lights Can Be Added
Fluorescent lights may not even be necessary if the case is beside a large window that gets some sun.
However, an electrical fixture holding at least two 48-inch tubes should be provided in the average room.
The additional light helps plants grow; it creates a dramatic display in the evening.
Use a fixture complete with a reflector, the maximum length that will conveniently fit into the case.
Although I have gotten along quite well with a two-tube fixture, even with no outside light, a four-tube unit would greatly increase the effectiveness, especially if you plan to use the case as a room divider or in any other place away from a window.
Hanging the fluorescent lights is easy. Place a screw eye in each of the four upper inside corners of the case. From each of these, bring a length of a small chain into the fixture and attach it with S hooks.
The fixture should hang 2″ or 3″ inches below the top of the case. Finally, near the top at one end, drill a hole in the wood large enough to put the electrical cord through.
If you intend to use a timer to regulate the lights, attach this outside the case.
Most cases have wooden floors that need waterproofing to prevent rot and warping. There are several ways of doing this.
An easy one is to line the bottom with a double layer of polyethylene film. Several coats of marine varnish would probably do as well.
A more permanent method is to use melted paraffin. Melt the paraffin in a coffee can in a pan of boiling water, then pour it all around the bottom of the case, forming a 1/8-inch thick seal. About two pounds of paraffin is enough for a case.
Unlike polyethylene or varnish, paraffin does not decompose but will crack if the case is moved a lot. Therefore have the case where you want it before completing this step.
The exposed wood inside the case should get a coat of marine varnish or water-resistant preservative to protect it from humidity. Finish the outside however you wish.
Since there is no drainage, use porous rather than rich soil. The growth rate of plants then can be easily controlled using water-soluble fertilizer.
An inch layer of vermiculite or perlite spread over the paraffin will absorb excess water.
For soil, I mixed two parts of peat moss, two parts of sand, one part of leaf mold, and a sprinkling of charcoal. This has proved satisfactory for free-growing ferns and mosses.
Many things can be done to give the case more interest. The soil level can slope from an inch in front to 8 or 10 at the back. Place a small strip of wood in front of the sliding doors to contain the soil.
Pieces of moss-covered wood and stones may create a natural-looking scene. Several large accent plants should be put in next, placed where they seem natural.
Don’t overcrowd them. They show better when there are only four or five.
I like to keep larger plants in individual pots. This makes it easy to remove them when desired, to go elsewhere in the house, or outside during the summer. And it is easy to control each plant’s soil and water requirements.
Little Plants For Background
Once the specimen plants are placed, the ground cover is put in Mosses, and vines or creeping plants can be used.
Baby tears (Helxine soleirolii) work well but may grow out of bounds. Selaginella kraussiana forms a compact, bright green mat. Its variety ‘brownie’ makes fluffy mounds.
Little plants can fill in between the specimens—prayer plants, peperomia, small ferns, and other small terrarium plants.
You can use adjustable shelves, which usually come with display cases, to increase variety. Put the shelf about 15″ inches below the lights.
African violets, wax begonias, gloxinias, and hanging plants like columnea and episcia grow to perfection there.
Some nepenthes hybrids I started from seed a year ago are beginning to form their first true pitchers now.
Almost any greenhouse plant can be grown in this case, but not all kinds simultaneously. Much depends on the temperature and light.
With the case on a cool sun porch, woodland plants would do well, also cyclamen and azalea.
A warm sunny location would grow jacobinia, or seedling orange and grapefruit trees.
Try some orchids that need warmth:
- Cattleya
- Epidendrum
- Dendrobium
It had good results with the bougainvillea ‘Barbara Karst,’ which burst into color during the darkest January.
Most plants will flower under lights. The gesneriads (African violets, gloxinias, episcias) are always more than willing. My interest is bromeliads.
The species of billbergia are especially good. They maintain their color and shape well and bloom freely.
Among the species, zebrina, saunders, and leptopoda (the permanent wave plant) are exceptional performers.
Vriesea splendens, that most striking of all bromeliads, and most of the tillandsias require the humidity the case can provide.
Ferns also make good specimens. Two outstanding ones are the maidenhair (Adiantum cuneatum), and the bird’s nest (Asplenium nidus).
Ferns provide an extra surprise. Before long, the bottom of the case will be covered with hundreds of small green disks in a few months. tiny new ferns will emerge.
These can be potted up when they reach the right size.
My display case greenhouse proved to be ideal for starting seedlings and cuttings. Seedlings should be within 3″ inches of the lights. Cuttings can simply be hidden among the plants at the bottom of the case.
African violet fanciers might want to dispense with the “scenery” and cover the bottom of the case with pots, suspending lights just above them.
The second tier of plants and lights could then be installed above this.
44659 by Roald Dahl Tweet