Perhaps the most important single factor in the failure of houseplants in the average home is the lack of humidity.
Increase Humidity
It is not easy to raise the percentage of humidity in the average home, but it can be done, and here are some of the measures that will help.
- Reduce the temperature by setting the thermostat at 68° degrees Fahrenheit during the day and 58° degrees Fahrenheit at night. (The moisture-holding capacity of the air decreases with a decrease in temperature, and the percentage of relative humidity is, therefore, higher.)
- Grow many plants; the transpiration of moisture from the leaves plus evaporation from the surface of the soil and the sides of the pots (provided they are porous such as the ordinary baked red clay pots) helps considerably.
- Another way to increase the humidity near the plants is to stand the pots on pebbles in a watertight tray. The water in the tray should be constantly maintained at a level that comes within / an inch or less of the surface of the pebbles. Among the satisfactory materials are turkey or chicken grits, perlite, coarse sand, or vermiculite.
Bay Window
A bay window is a great asset, especially if it is equipped with a watertight tray, 1” to 1 ½” inches deep. It can be made from galvanized sheet metal which may be given a coat of asphalt paint to protect it from rust.
If you are a “do-it-yourself” addict, you can make a wood frame 1” to 3” inches high, lining it with aluminum foil or heavy polyethylene film.
There are trays commercially available that are designed to be placed on radiators. This enables one to grow plants on an active hot water radiator. A converted aquarium is also effective.
Another Way To Increase Humidity
Another way to increase the humidity of the air is to spray the plants three or four times a day.
The tools used can be a quart sprayer or a fog nozzle outfit, as used in mist propagation. Or it is possible to buy an honest-to-goodness air humidifier capable of vaporizing 5 to 6 gallons or more of water a day without any visible drops of water.
If old-fashioned steam radiators heat your house, you can get water containers to hang on them; these should be inspected daily and refilled if necessary.
If you have a hot air system, usually a humidifying device is built into the furnace.
Use Wardian Case
With a Wardian case or terrarium, you can get the humidity percentage in the high 90s if you want it that high.
A Wardian case is a glass or transparent plastic enclosure, essentially a small greenhouse.
Construction is quite simple. You will need something to hold the soil and attach the frame to support the polyethylene film.
A box about 4” inches deep, 8” to 10” inches wide, and 12” to 24” inches long will serve. The size depends largely on the space available.
The frame can be made of galvanized wire, coat hangers, or flexible willow fastened inside the box by staples. Thumb tacks can fasten the polyethylene to the box, or the ensemble can be slipped into a plastic bag used by dry cleaners.
Glass can be used by cutting two pieces about 18 inches tall, the exact length of the inside measurements of the box; two end pieces the same height as the sides should be cut to the inside dimensions of the box with the two thicknesses of the glass side walls deducted.
These are held in position by the soil filled In and/or by taping the corners with adhesive tape. The “roof” (which is. for most plants, not essential) is made of a piece of glass that conforms to the outside measurements of the box.
Plunging Pots
The plants are grown directly in the soil or kept in pots, which are plunged to their rims in peat moss, perlite, or vermiculite.
The advantage of plunging the pots is that whenever it may be necessary, you can remove a plant without disturbing the roots of its neighbors.
Whether the box should be watertight or not depends on your ability to estimate the amount of water to be added to keep the soil uniformly moist without waterlogging it.
If the box is watertight and the cover also is tight, it can go for a month or more without any attention whatsoever.
On the other hand, if you have drainage holes in the bottom, the danger of waterlogging is reduced, but you will need a watertight tray to stand the case to catch the drainage water.
Bubble bowls and brandy snifters may be used with or without glass covers. These transcend the rules which say drainage must be perfect and fresh air must be provided, but they do need great care to avoid overwatering.
Apart from this, they are practically foolproof. Those which are almost hermetically sealed have gone for months with no attention.
If, for any reason, you cannot put these measures into effect, there are still many tolerant plants that will grow in your home. These are found chiefly among the xerophytes, usually plants of desert regions.
There are some natives of tropical jungles who, because of their locations as tree “perchers.” have to get along as best they can when their rooting medium dries out, as it does during the dry season.
Drought-Resistant Plants
Among drought resistors are many plants in the bromeliad (pineapple) family, such as Bromelia Lasantha, Cryptanthus zonatus, and Billbergia nutans. Then there are various aroids, members of the Jack-in-the-pulpit family.
Among the most satisfactory of these are various species of philodendron, monstera, dieffenbachia, and anthurium.
The crassula family contains many suitable kinds, such as Myriophyllum, kalanchoe, sedum, and sempervivum. Plants in the pepper family, including peperomia and piper, are also toughies.
Cactus is another group that is generally amenable. These usually require plenty of sun, although some, such as the Christmas cactus, Zygocactus truncatus, and the orchid cactus epiphyllum, get along well in partial shade.
Sansevieria
Sansevieria or snake plant, is, I believe, the toughest of all house plants. The only conditions that will cause it to fail are too much water or freezing.
I have it in a dish garden along with plants in other genera — Haworthia, peperomia, opuntia, Piper, mesembryanthemum, and Crassula.
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