“Most people spend more than 90% of their time indoors”. Several volatile organic compounds released either by certain human activities or indoor existing materials e.g. paints, cleaning products, varnishes, glues, etc. These VOCs are the primary causes of indoor air pollution. Indoor air needs to be purified in the same way as outdoor air because a polluted indoor environment could become the source of several breathing disorders, chronic obstructive pulmonary disease, lungs cancer, etc.
Following are the NASA recommended indoor air cleaning plants that are not only the source of oxygen production and CO2 absorption but also removes the toxic volatile organic compounds including benzene, toluene, ethylene, formaldehyde, etc.
1. Rubber Plant (Ficus elastic):
Baby rubber plants (rubber trees and shrubs also available for large closed areas) are usually grown indoors. It is a broad-leaved plant. Rubber plant's leaves excellently absorb VOCs (volatile organic compounds), pass them through their internal system to the roots where these contaminants are either processed or absorbed by the soil microbes. The second advantage of this handsome plant is to produce fresh Oxygen for your room/office and takes in carbon dioxide quite rapidly as compared with the other plants and again, partially due to its high surface area leaves. (Zhu & Jin, 2019)
Care and requirements: It prefers indirect, dim light, under-watering than over-watering, and do not demand frequent maintenance. Rubber plants can be grown up to 8ft. in height under stable indoor conditions.
2. Areca Palm (Dypsis lutescens):
Royal Horticultural Society has awarded Areca Palm with “Award of Garden Merit” based upon its physical as well as air cleaning properties. It can absorb VOCs including toluene, xylene, formaldehyde, and benzene. It takes in CO2 and takes out Oxygen to maintain a healthy indoor environment. Two areca palms of average size are enough for a space of 100sq. ft. to keep a balanced gaseous exchange. However, the no. of plants will be numbered according to the no. of individuals in a room/office. (Bhargava et al., 2021)
Care and Requirements: Proper nourishment and regular repotting (it needs well-aerated soil) are essential elements to keep the palm green and healthy. It requires medium light and grows up to the height of 6-7 ft. The average life span of an Areca palm is 10 years.
3. Snake Plant (Dracaena trifasciata):
Like all other indoor succulents, the snake plant which is also known as Mother-In-Law’s Tongue serves to purify the indoor air. It’s additional quality is to remove formaldehyde, toluene, trichloroethylene, and xylene through Phytostabilization. The Snake plant is good to keep in bedrooms, offices, hospitals, and shopping malls too. It has a unique character of producing Oxygen at night time. Six-to-eight waist level plants are enough for one person to breath in a sealed room. (Chauhan, Rawat, & Gauba, 2017)
Care and Requirements: Water the plant weekly, it prefers bright light, and often tolerate direct sunlight. However, grows well in shady areas too. The Indoor temperatures most favorable are 65-80°F
4. Money Plant (Epipremnum aureum):
Approved by NASA, this cute tree is an excellent indoor air purifier. One of the special features of a money plant is that it can be grown efficiently in both soil and water. It will absorb air pollutants such as toluene, formaldehyde, etc. wherever present indoor. It is a must-have indoor plant due to its ornamental and easy-to-maintain properties. (Dongliang, Xiaomin, & Zhe, 2017)
Care and Requirements: Money plant leaves may be toxic for pets and children if ingested. The solution is to establish it high on walls or windows out of reach. It requires indirect light and moist soil.
5. Chinese Evergreen (Aglaonema commutatum):
Both in living and working places, Aglaonema performs the function of air purification. It releases Oxygen and absorbs carbon dioxide, benzene, xylene, and formaldehyde. It is one of the most commonly grown and widely researched indoor and outdoor plants in China for its phytoremediation properties. (Ghate, 2016)
Care and Requirements: Aglaonema prefers full shade, moist soil, and a frost-free environment. It cannot tolerate dry air and frost. Never over water, just keep the soil surface moist.
6. Spider Plant (Chlorophytum comosum):
Spider plant also named “Ribbon Plant” is a gorgeous, perennial house plant. It is a non-toxic (also edible for the animals) plant and easiest-to-maintain kind of plant. It absorbs VOCs such as formaldehyde, xylene, and carbon monoxide. (Giese, Bauer-Doranth, Langebartels, & Sandermann Jr, 1994)
Care and Requirements: Requires bright to moderate light, weekly watering in summer and spring, and monthly during winters. You can easily propagate spider plants through Spiderettes and develop basically as many plants as you want.
7. Gerbera Daisy (Gerbera jamesonii):
“G” for Gorgeous and “D” for Distinctive, Gerbera daisy hides its remarkable features in its name. It is an annual flowering plant and most homeowners over-winter them indoors. Gerbera is an excellent Oxygen releasing (at night) and VOCs absorbing plant. The people suffering from breathing problems or sleep cycle disturbance are recommended to keep Gerbera in their rooms (2-3 plants are enough).
Care and Requirements: Gerbera remains happy in moist soil and moderate light conditions (in winter and bright light in spring, summer). You can grow two sets of Gerbera (each of 2-3 plants), one for indoor and the other for outdoor. Keep exchanging indoor with the outdoor set to provide them with sufficient sunlight.
8. Aloe Vera:
Aloe Vera is a lovely and multi-purpose succulent. Aloe Vera jell can soothe and heal burns, cuts, etc. It absorbs VOCs such as formaldehyde and benzene found in detergents, varnishes, and paints. It is widely used in skin care products and medicines. It grows in a beautiful manner making your indoor spot worth looking at.
Care and Requirements: it thrives best in moist, well- drained soil and sunny locations. However, the full sun may cause wilting of aloe leaves. It does not require frequent maintenance, so easy to grow for beginners in planting.
9. Dracaena (Dracaena fragranse):
The ornamental feature of Dracaena leaves is their unique bright red trim. These plants also have air cleaning properties as they absorb xylene, benzene (46 %), and trichloroethylene. (Wolverton & Wolverton, 1993)
Care and Requirements: It demands brightly filtered light (no direct sunlight), try to keep the leaves hydrated but never over-water the plant.
Chrysanthemum is a mini Phytoremediator. It absorbs air contaminants efficiently and its vibrant colored flowers will provide a fresh look to your room. Some perennial varieties of chrysanthemum such as football mums, spider mums, etc. are available in the markets to grow indoors.
Care and Recommendation: chrysanthemum demands bright light for its functionality, so you can place them in windows, in front of doors, balconies, etc. where they can receive sufficient light for 7-8 hours.
11. Broad-lady Palm (Rhapis excelsa):
Rhapis excelsa is an expensive but efficient indoor air purifier. It removes the four major VOCs including formaldehyde, benzene, ammonia, and CO2 from the indoor air to make it safer for breathing. The lady's palm is not toxic for the animals. (Aini Jasmin, Noorizan, Suhardi, Murad, & Ina, 2012)
Care and Requirements: It lives happily under indirect-moderate light, at room temperature, and in humid environments. It can be placed in the living rooms, bathrooms, and east-facing windows.
12. Poinsettia (Euphorbia pulcherrima):
More than 8 million poinsettia plants are sold every year in the UK as house plants or for Christmas decorations. Poinsettia is an ornamental plant known for its bright red and green colored foliage. It has good air cleaning properties too. Grow it to clean your indoor air and enjoy them while doing so! “Rubi” is a new indoor cultivar of Poinsettia. (Canul-Ku et al., 2018)
Care: Poinsettia remains healthy and happy under indirect, 6-7 hours of light, less water, and room temperature i.e. 65-75 ˚F.
Some Less Commonly Used But Good Air Cleaning Plants:
Below is a list of ten less commonly grown indoor plants recommended by NASA to have exceptional air purification properties: