Tropical plants will flourish as indoor house plants when given the proper care and conditions. To keep your tropical plant leaves healthy, they require the proper amount of nutrients, humidity and rest. In addition, cleaning or polishing the leaves allows them to get adequate air and keeps your tropical plants looking their best
As with any plant, tropical plants require the right nutrients to thrive. Of the three main nutrients that plants need, (nitrogen, phosphates, and potash), nitrogen is the nutrient that promotes healthy foliage. Tropical plant leaves with a pale, washed out appearance or yellow spotting indicate a need for fertilization. Plant leaves that are wilted or have crisp brown spots or scorched edges indicate that the plant is getting too many nutrients.
In a heated room, the air is dry. Tropical plants require higher humidity for healthy foliage. Too little humidity is indicated by leaf tips that are brown and shriveled, or leaf edges that are yellow or wilted. To increase humidity, mist with tepid water each morning. Grouping plants together also increases humidity, as plants receive moisture that rises from the damp compost of the surrounding plants. Another way to increase humidity is to double pot tropical plants with moist peat moss placed between pot and container, or fill drainage trays with pebbles that absorb moisture and release it into the air, according Dr. D.G. Hessayon in the 1993 book "The Houseplant Expert.".
Most tropical plants require a dormant period, where they receive less water and fertilization, as well as less sunlight. Cooler conditions may also be required. This period usually occurs during the winter months, when growth slows. Regular watering and feeding can be resumed, and plants can be moved back into warmer temperatures when new spring growth appears.
Dust spoils the appearance of foliage and blocks leaf pores, so the plant can no longer get the air it needs. Dust also blocks light, so keeping leaves clean is important. Clean foliage by sponging he leaves, or immersing smaller plants in water. Be sure to wash both sides of the leaves to open pores thoroughly. Clean foliage early in the day, so the plant will be thoroughly dry by nightfall. Very dirty leaves should be dusted with a soft, dry cloth before washing to prevent mud that sticks to the leaves when they dry.
Many tropical plants have large, smooth leaves that tend to become dull and tired-looking as they age. The glossy new-leaf look can be restored by polishing the leaves with one of the plant polishing products that is available on the market. There are both wipe on liquids and aerosol sprays are available that are made especially for plants. Polish only old leaves that have lost their luster and never press down on the leaf surface, Hessayon advised. Check product labels for a list of plants that the product should not be used on.
Numerous University Cooperative Extension Services warn against using leaf-shine products as they can interfere with "transpiration," evaporation of water from leaves, and actually attract dust, according to Colorado State University Extension. Arizona State University Extension recommends using non-lanolin baby wipes on leaves.