You don't have to live in the tropics to enjoy the exotic look of tropical plants. Numerous varieties of tropical house plants are sold in nurseries throughout the country. Varieties range from exotic to somewhat common and include African violets, orchids, philodendron, bougainvillea, begonias and tropical corn plants. Care of your tropical plants begins at purchase and continues for years to come. Temperature, moisture and sunlight as well as pest and disease control all factor into the health of your plants. Though tropical plant care varies from species to species, there are a few general principles to follow.
When dealing with tropical house plants, the Texas Master Gardener Handbook, compiled by Texas A&M University, says there are three aspects of sunlight to consider: intensity, duration and quality. Light intensity is impacted by the direction of windows in your home as well as window shades and outdoor influences such as trees and shade from buildings. Southern windows offer your plants the most intense sunlight, followed by eastern and western windows. You can increase the intensity of light inside your home by using reflective surfaces.
Most house plants, including tropical plants are divided into high-, medium- and low-light varieties, referring to light intensity combined with light duration. High-light tropical plants include jasmine, small lemon and lime trees and bougainvillea. African violet, ficus and lady palm do well in medium light and philodendron and dracaena are low-light plants. A good rule of thumb, according to Lowes.com, is to remember that plants that flower or have colored leaves need higher levels of light than non-flowering plants with green leaves.
Light quality refers to the wavelength of artificial lighting. Natural sunlight produces full-spectrum lighting while most artificial lights do not. Plants need red (long wavelength) and blue (short wavelength) light for photosynthesis. And a combination of blue, red and infrared light is needed for flowering. Incandescent lighting tends to produce good red and infrared light, but not much blue. It also emits excessive heat and is not very energy efficient. Cool white florescent lights provide blue light, which is good for foliage, but its red and infrared light varies. If you are depending heavily on artificial light for your tropical plants, purchasing specialty grow lights might be your best option.
You can divide tropical plants into three watering categories: moist, slightly dry and dry, according to Stauffers of Kissel Hill Gardening Center. Moist-soil plants prefer their soil to never dry out. Most tropical house plants, however, are not moisture loving and will suffer root rot with too much water. For slightly dry plants, which many tropical plants are, you should let the surface of the soil become dry between waterings. For dry varieties, press your finger deep into the soil to ensure the bottom two-thirds of the soil is somewhat dry before watering. You should water your plants more often during periods of active growth than during seasons of dormancy.
Temperature and Humidity
According to the Texas Master Gardener Handbook, preferred daytime temperatures for both flowering and non-flowering tropical house plants ranges from 70 and 80 degrees Fahrenheit. Nighttime temperatures vary, however, between flowering and foliage plants. Flowering plants preferring cooler nighttime temperatures between 55 to 60 F while foliage plants prefer 60 to 68 F at night.
Most tropical plants do like humidity and are willing to sacrifice a few degrees of warmth if needed to receive it. The warmer your house is, the drier the air, especially if you are using a forced-air heating system. To increase humidity for your tropical plants, mist leaves periodically with a spray bottle or use a humidity tray of pebbles and water beneath it. As the water from the tray evaporates, it will increase the relative humidity in the air.