Dry air creates problems with growing tropical houseplants here in Arizona. Anthirium, philodendron, schefflera and other leafy types are adapted to humid regions of the world, but they struggle in desert air.
We have to keep in mind that initially they are grown in greenhouses, where the air is moist.
Extra watering will not correct the problem of low humidity; overwatering only makes the problem worse. Even though the soil is wet, it won’t solve the problem; if the air is dry, the leaves lose water faster than it can be replaced from the roots. Root rot can occur if the roots are kept too wet; then leaves get even less water from the roots to replace moisture lost to the air.
Even on a good day, the air inside our homes is still dry. When our homes are closed up, especially in the winter with the heat on, they become bone-dry. As a result, houseplants suffer.
Dry air is one reason why plants develop brown tips and leaf margins. As leaves dry, the tips turn brown, then the margins of the leaves turn brown, and finally, the lower leaves become yellow and drop. Some plants are sensitive to the fluoride and chlorine in tap water. Spider plants, Ti plants and Spathiphyllum are most commonly affected by fluoride, developing brown leaf tips as a result.
Excess salts from fertilizer and water can also cause leaf tips to brown.
Occasionally, accumulated salts need to be leached out of the soil. To do this, apply large amounts of water repeatedly to dissolve the salts and wash them out of the bottom of the pot.
Keep the soil moist, but not wet. Pots should always have drainage holes. Moisture meters can be an effective tool in determining when your plants need water. Just make sure you push the probe down toward the bottom of the pot. If the soil there is still wet, wait to water.
There are many ways to combat dry air indoors:
• You can use a humidifier to keep the air in a room or a section of your home moist.
• Another way to put moisture in the air is to set your plants on gravel-filled plates. The plates should be oversized to allow the moisture that evaporates off the gravel to flow up around the leaves. The gravel also supports the pot, preventing the potted plant from actually sitting in the water. Keep water in the plate at all times, filling it up to just below the bottom of the pot. Fine aquarium gravel, available at pet stores, works best. The smaller the gravel, the greater the surface area there is for water to evaporate. The greater the evaporation, the greater the humidity will be.
• Grouping plants together indoors also helps to keep the surrounding air moist. This is because plants lose moisture to the air from pores in their leaves. The process is called transpiration. This combined transpiration, or moisture loss by several plants, increases the humidity.
• Position plants away from heater vents and in the coolest rooms of the house. The air won’t be as dry in these locations. When light is adequate, also place plants in the kitchen or bathrooms. Moisture from baths, showers and cooking will increase the humidity for short periods of time.
Contrary to popular belief, misting plants with water from a spray bottle will not keep them from drying out. So unless you can squirt your plants every five or 10 minutes around the clock, use a method with longer-lasting effect. In the time it takes the moisture to dry from the leaves, the air becomes just as dry as it was before.
Why not grow cactuses and succulents? Hundreds of beautiful and interesting varieties are available, and they can’t be beat for toughness.