For the past two centuries, mankind has been playing with houseplants as if they were pretty toys. We have appreciated their beauty and suspected their power to enrich our lives, yet we are only now learning how they also can foster something everyone wants: to feel happy. The science of happiness is still in its infancy, but houseplants, it seems, have been doling out doses of happiness for a long time. And, with the increasing availability of bright blooming houseplants (which get the highest smile ratings), more and more people are discovering the joys to be found in indoor gardening.
We hope you are one of these people. This book is designed to meet the needs of house-plant growers of all skill levels, from newbies, who often feel a bit anxious about doing the wrong thing and causing their plant to suffer, to experienced plant keepers, who sometimes want to know more about a plant’s background and superior forms that might be available. The plant profiles in Parts 1 and 2 describe how to care for 150 beautiful blooming and foliage houseplants, including many selections that have entered retail markets only in the last ten years. General information on houseplant care is covered, encyclopedia style, in Part 3.
Before we jump into that green world, a short review of how houseplants came to be is in order, as well as an inventory of the benefits they bring to the people who grow them. When it comes to houseplants, history, healing arts, environmental sciences, and interior design intertwine in unique and life-enhancing ways. Expanding your awareness of what house-plants can do will give you a new appreciation for indoor plants wherever you are lucky enough to encounter them — from the waiting room at your dentist’s office to your own kitchen windowsill.
When did people begin keeping indoor plants? It wasn’t so long ago, because people had neither plants nor hospitable indoor environments until modern times. The forerunners to houseplants were medicinal herbs, which monasteries and apothecaries struggled to keep alive in dim, drafty indoor spaces when protected courtyards would not do. The advent of glass windows (which began appearing in Europe in the late 1600s but were not commonplace for another 200 years) were quickly followed by the culture of citrus fruits — the first plants to be widely grown “under glass” in early conservatories. But it was not until plant exploration boomed in the nineteenth century, coupled with the increased availability of window glass, that people had real choices in houseplants and suitable environments in which to grow them. Blown-glass tableware, and even stained glass, predate clear window glass by several hundred years, because forming molten glass into a flat surface is much trickier than creating small pieces or variously shaped bubbles. It’s interesting to imagine the excitement people felt when window glass made it possible to enjoy indoor light year-round — a huge change from pulling closed dark shutters every time a cold wind blew. The next step was to see if plants could also make use of light that came through wavy glass windows.
Social changes supported the move to grow plants indoors. During the Victorian era (1837 to the early 1900s), a nicely kept formal parlor became a symbol of middle-class respectability, and a proper parlor included plants. Many of these plants remain popular today because of their ability to adapt to low light — aspidistra, sanseveria, ferns, and palms. Geraniums also became a fashion craze, and small terrariums planted with tiny tropicals provided the middle class with miniature versions of the glassed-in conservatories kept by the rich. In 1936, George Orwell used the aspidistra as a symbol for the English middle class’s preoccupation with propriety in his comic novel Keep the Aspidistra Flying.
Miniature greenhouses, or terrariums, were one of the first methods employed for keeping plants indoors.
Meanwhile, in North America, the first half of the twentieth century was a quiet era for houseplants, but they came back into style with a vengeance in the 1960s and 1970s. As part of the back-to-nature movement, people got into green things again, and a new generation of plants was ready to fill the need. Dorm rooms were decked out with dracaenas and philodendrons, and sparsely furnished apartments became jungles of jade plants, crotons, and cacti. Then, as the flower power generation became more involved in careers, raising families, and keeping up yards, their houseplant collections thinned.
But changes are afoot. The generation that embraced houseplants in the 1970s is rediscovering old green friends and making many new ones. The roles houseplants play in peoples’ lives have changed, too. Instead of symbolizing social status or the need for a cleaner, greener world, houseplants are valued for all the things they do, from providing companionship to purifying the air to helping fragile bodies heal. We no longer grow houseplants to impress other people. We grow them to please and nurture ourselves.
We assign our plants personalities and genders, and even guess at their taste in music. Like animal pets, plants welcome us home when we’ve been away, respond to our care by growing healthy and strong, and draw us into very real relationships. This process can be healing in itself. When people have been badly hurt by others, or face the task of rebuilding a shattered life, therapists and recovery programs often suggest that they begin healing by nurturing a houseplant. Even a simple relationship such as that between a pothos and its keeper is rife with lessons about understanding, responsibility, and patience.
Clockwise from top: Dendrobium (spray orchid), clivia, Faucaria (tiger’s jaws)
Popular gift plants include (clockwise from left) tulips, cineraria, begonias, hyacinths, and primroses.
Our subtle belief in the healing power of indoor plants is reflected in the gifts we send to those who are sick and grieving. As well as the message to “Feel better,” remember that you can use living plants to send other positive messages: “Good luck in your new business venture,” “Congratulations on your new home,” and “Thanks for a job well done” are commonly written on notecards accompanying houseplants to their new homes. At work and at home, houseplants enter our lives as legacies that remind us of milestone events.
Indeed, more houseplants are given as gifts than are intentionally selected by the people who want to grow them — and sometimes this creates a problem. We are often faced with the challenge of accommodating a plant chosen by others because of its beauty, and this story does not always have a happy ending. If you’ve struggled in the past to please gift plants that never seemed satisfied, don’t be discouraged. Instead, get to know the best sites you have for growing houseplants, and choose species that are likely to prosper. The returns for sharing your home or office with vigorous plants are enormous.
The workplace has become home to many pet plants, which is good for workers, employers, and their customers. When you set aside a little space in a work cubicle for a leafy friend, its constant companionship is soothing to the body, mind, and soul, which improves your morale.
The presence of plants at work has other payoffs. Plants actually make for better work, as has been validated in several studies. For example, in a five-story office building in England, four stories were stocked with houseplants. A year later, a clear correlation was found between the plantless floor and increased absenteeism and reduced productivity. In a controlled experiment at Washington State University, students working in a computer lab were more productive and made fewer mistakes when houseplants were within easy view.
Several other studies have found that house-plants improve students’ performance in schools. Because so many bodies are present in classrooms, all breathing in oxygen and exhaling carbon dioxide, carbon dioxide levels are often four to five times as high as they should be. Plants take in carbon dioxide and give off oxygen, so they are a natural choice for helping to set things right. Numerous school systems now recommend keeping classrooms, corridors, and cafeterias well stocked with houseplants. Reducing high carbon dioxide levels helps students stay alert while creating a much more wholesome environment for learning.
The explanation for improved work and school performance in the presence of house-plants goes beyond plants’ abilities to restore healthful oxygen levels. After all, if we could feel smart and positive and well by breathing more oxygen, we would all be walking around wearing oxygen tanks. It is also likely that, in addition to the oxygen plants are putting out, their benefits encompass what they are taking away. As part of their normal transpiration processes, house-plants also clean the air of gaseous chemicals.
NASA scientists have validated the ability of many plants to remove from the air pollutants ranging from ammonia to xylene. Paints, carpeting, furniture, and even our clothing give off pollutants, which can build up to toxic levels in tightly insulated spaces. Houseplants ease this situation (though a large number of houseplants are needed to purify badly tainted air). In new homes or buildings, where indoor chemical pollution is likely to be most acute, a strong case can be made for bringing in as many green plants as the space can hold. Among houseplants, the most efficient air purifiers are heavy transpirers, or species that cycle a lot of water from roots to leaves, such as palms, rubber plants, and corn plants (Dracaena). However, any green plant deserves some credit for making indoor air better for people to breathe.
It is a fact that being near plants improves the quality of every breath you take, but excellent air does not fully explain how a houseplant sitting on the corner of a desk can improve test scores, or how plants in a room increase a hospital patient’s tolerance for pain. Even a simple green scene, such as a sanseveria stationed in a classroom window, can soothe and inspire while quietly ridding the air of excessive carbon dioxide. Clearly, living with plants is good for us, so it makes perfect sense to share our indoor space with generous green friends.
Low-maintenance sanseveria provides the calming effect of plants at the same time that it purifies the air.
There may be more to this story, because certain aspects of our relationships with plants are beyond the scope of science. Yet there is one basic principle that may be at work here. The green world of trees and grasses is our natural home. It’s where we got our start, and though climate-controlled indoor spaces are comfortable, something important is missing. That something affects our attitudes, work performance, ability to tolerate physical and emotional discomfort, and other variables that add up to happiness.
An eye-catching assortment of easily grown succulents.
In making the case for houseplants, one unsung variable is creativity — another fascinating characteristic unique to humans that, when worked regularly like a muscle, makes us feel vibrantly alive. Enter the practice of interiorscaping, in which plants are used as living art. The large windows present in modern homes and offices, particularly those employed in passive solar design, create ideal canvases for tapestries of foliage. Where windows are not available, green plants grown beneath bright supplemental light dramatically transform the mood and vibrancy of any indoor space.
Indoors as well as outdoors, artfully arranged plants evoke a feeling of completion that goes far beyond fads or styles. The business world has learned that good interiorscaping creates the impression of prosperity, which is tightly linked to customer confidence — a well-trodden path to success. Perhaps this is why houseplants are so popular as gifts to new businesses. They also create a welcoming environment in airports, malls, and other public places, where a high priority is given to making the place feel comfortable and inviting.
Wherever houseplants live, they must be given appropriate care in order to flourish, which is the main goal of this book. Whether you enter the houseplant world on purpose or by accident, good care gives plants a fair chance to proclaim themselves as the sovereign life forms that they are, eager to demonstrate their ability to enliven a tabletop, windowsill, or vacant corner. As a plant’s keeper, you become part of its performance. This book will be your tutor in that role, so that as you include plants in your interior spaces, you, too, will come a little closer to having a happy life.
The world of houseplants is huge and varied, so this book is organized to help you quickly and easily find the information you need. It is divided into three main parts — two plant directories and an in-depth encyclopedia of houseplant care. The first A–Z plant directory contains information on blooming houseplants, which are grown as much for their flowers as for their foliage, and the second A–Z directory covers foliage plants, which typically do not produce flowers. Each directory is alphabetized by botanic name: For a translation of botanic to common, and common to botanic names. (For an explanation of botanic nomenclature.)
Within each A–Z directory, groups of closely related plants (for example, several kinds of cacti in the blooming section and several kinds of ferns in the foliage section), are discussed together, since they share common needs. The whys and hows of caring for these plants are covered in detail in short introductions to each group. The introductory coverage often includes a reference chart to help you compare the characteristics and cultural requirements of individual species and a group roundup of frequently seen problems. Each species then gets its turn in the spotlight.
Many houseplants stand alone, with no close relatives with whom they might be confused. The plant profiles describe each plant’s size and appearance, its preferred growing conditions, the best methods for propagating the plant, and tips for selecting varieties and displaying them to maximum advantage. The individual profiles conclude with a troubleshooting section to help you identify and correct common plant problems. If you find the remedies given in the troubleshooting sections too brief, look at the more detailed information in Part 3: Houseplant Care. If you have any questions about the terminology used in this book, you can consult the Glossary.
If growing houseplants is a new venture for you, or if you think you may not be able to provide the right spot for many of them, look for this icon at the top right of some entries. These are the plants that thrive in a wide range of light and temperature conditions or aren’t very fussy about their water needs.
Plants that don’t get this signal aren’t necessarily difficult to grow, but check out the 
in the specifications. This indicates that if you pay attention to that particular need, you’re more likely to succeed with that plant.
The first step is to identify the houseplant you want to study. This may or may not be provided on a plant tag stuck into the pot. If you know either the plant’s botanical or common name, you can look at the botanic-to-common or common-to-botanic cross reference lists or the index to locate detailed information about the plant. But often foliage plants, in particular, are simply labeled “foliage plant” or “tropical plant.” Use the following Plant Identification Guide, which is designed to help you name your plant, and then refer to the entry in Part 1 or 2 for all you need to know to help it not only survive, but thrive.
If you find yourself feverishly interested in a certain type of plant, look into the plant societies and specialty mail-order nurseries listed in Resources for Houseplant Lovers. These organizations and companies share your passion and can greatly add to the satisfaction of growing beautiful houseplants.
IT’S NOT UNUSUAL TO ENJOY YOUR HOUSEPLANTS without knowing their names. Cuttings from friends, supermarket finds, or even plants from nurseries may not be identified, or may be identified incorrectly. But with a proper identification, you’re more able to meet your plant’s needs. This key helps you observe and classify your plant’s characteristics, starting with 5 main, color-coded categories:
• Plants with small “oranges” present
• Plants with no spines but with flowers
• Plants with no ordinary leaves
• Plants with no spines and no flowers
• Plants with spines or hairs on leaves or stems
For instance, your plant has smooth stems (no spines) but it does have flowers, so you go to the heading “No spines, flowers present,” where you have 4 more choices. Because your plant has very showy flowers and plain green, straplike leaves, you’re led to 6 plants that fit that description. Make your match by comparing the photo and description to your plant. Note: Plants listed as “no flowers present” may in fact bloom, but the key was developed to help you identify them either way. Also, the term “flowers” in this chart may refer to colorful bracts.
• Citrus × citrofortunella mitis (pp. 88–89)
• Solanum pseudocapsicum (pp. 148–149)
