Exploring the diversity, propagation, impacts, and market dynamics of houseplants: current trends and future prospects

Houseplants, often cultivated for their visual appeal, are typically placed indoors, on terraces, or on lawns. While their sizes can vary, they usually do not exceed 5.5 feet in height. These plants can range from cacti and succulents to small flowering plants such as orchids and African violets. However, the most significant group among them is foliage plants, which, despite not always producing flowers, are cherished for their unique and attractive leaves^[1]. Foliage plants form the backbone of the houseplant industry. As urbanization progresses and living spaces evolve, houseplants have become indispensable for creating environments that provide peace, coziness, and mental comfort. Moreover, the economic impact of the houseplant industry cannot be overlooked. The global market for houseplants has seen substantial growth, driven by increasing consumer awareness of their benefits and the rise of urban living. As people move to cities and living spaces become more compact, the need for greenery and natural elements within homes has intensified^[2]. Houseplants offer a solution to this need, providing a touch of nature that can transform urban living spaces into green sanctuaries. This trend is further amplified by social media and digital platforms, where the aesthetic appeal of houseplants is prominently showcased, inspiring more people to adopt indoor gardening as a hobby or lifestyle choice. Beyond their aesthetic value, houseplants offer numerous benefits, including improving air quality, regulating room temperature and humidity, and fostering a positive environment. Research conducted in Japan, Norway, and the USA has demonstrated that indoor plants can alleviate stress, enhance productivity, and promote overall well-being^[3]. Due to these benefits and the increasing trend towards modernization, the demand for houseplants and their market is continuously expanding.

Marketing strategies in the houseplant industry have also evolved to keep pace with the growing demand. Retailers and nurseries are increasingly utilizing online platforms to reach a broader audience, offering a wide variety of plants along with detailed care instructions and tips. Subscription services for houseplants have emerged, providing consumers with regular deliveries of new plants and related accessories. These innovative approaches not only make it easier for people to acquire and care for houseplants but also foster a sense of community among plant enthusiasts. The global indoor plants market size is expected to reach USD${\$}$14.753 billion by 2030 (market-reports).

Conventional propagation techniques with comparatively higher propagation rates like division, cutting, and water propagation are being used rather than slow propagation techniques like seed propagation^[4]. In response to this growing demand, many developed countries have focused on the micropropagation of houseplants, enabling mass production and exportation^[5,6]. This surge in demand has also spurred the development of new plant varieties. Advanced technologies such as CRISPR-Cas9, alongside conventional mutation procedures, are now being employed to create new ornamental varieties of houseplants^[7,8]. Micropropagation, a form of plant tissue culture, involves the propagation of plants from small tissue sections in sterile conditions. This method allows for the rapid production of a large number of genetically identical plants, ensuring uniformity and high quality. Micropropagation techniques have advanced significantly, allowing for the efficient and cost-effective production of houseplants. This has not only met the rising demand but also facilitated the development of new and improved plant varieties. Through selective breeding and genetic modification, plants with enhanced aesthetic and functional attributes are being cultivated, catering to the evolving preferences of consumers^[9].

The prospects for the houseplant industry are promising. Continued advancements in micropropagation and genetic engineering are expected to yield even more diverse and resilient plant varieties. Efforts to improve sustainability in plant production, such as reducing the use of chemical fertilizers and pesticides, are gaining traction. Additionally, the integration of smart technology in plant care, including automated watering systems and sensors for monitoring plant health, is set to revolutionize the way houseplants are maintained. This paper provides a comprehensive review of the status of houseplant production, with a particular emphasis on in vitro micropropagation. It examines recent advancements and developments in the field, explores marketing strategies, and considers future prospects. By delving into the challenges and opportunities in this sector, we aim to contribute to the ongoing efforts to enhance the availability and diversity of indoor plants. This review will help stakeholders to understand the dynamic landscape of the houseplant industry and the potential it holds for future growth and innovation.

The commercial production of ornamental plants is expanding globally, with its monetary value significantly increasing over the past two decades. This industry shows great potential for continued growth in international markets. In developed countries, major potted plants such as Begonia, Ficus, Anthurium, Chrysanthemum, Rosa, Saintpaulia, Spathiphyllum, Philodendron, and many others (Table 1) are commonly kept as houseplants. With the extended variety in size, color, and leaf type, houseplants have some similar properties like aesthetic appeal and a vibrant look (Fig. 1). Driven by elevated value and demand, the rate of houseplant production has surged significantly. As reported by Pierik^[10], in 1991, approximately 212.5 million plants were produced, with 157 million of these classified as ornamental plants. This represents a substantial 78% of the total production, underscoring the prominence of ornamental varieties in the market^[10]. The variable of houseplant classification is versatile. However, houseplants can broadly be categorized into two types based on their light requirements: indoor and outdoor. Outdoor plants, which need both bright light and shade, include foliage plants, cacti, succulents, and ornamental plants. Popular ornamental houseplants include moth orchids, bougainvillea, and peace lilies. There is also a wide variety of vibrant and unique cacti and succulents favored as houseplants. Cacti are hardy with impressive growth rates, while succulents can be challenging to sustain in warm, humid climates.

Figure 1. 

Pictures of common houseplants. 1. Bougainvillea glabra, 2. Nephrolepis cordifolia, 3. Monstera deliciosa, 4. Philodendron angela, 5. Philodendron Florida, 6. Philodendron Birkin, 7. Dracaena trifasciata, 8. Aglaonema commutatum, 9. Caladium bicolor, 10. Echeveria gibbiflora, 11. Epipremnum aureum, 12a. Syngonium podophyllum (pink), 12b. Syngonium podophyllum (white), 13. Philodendron melanochrysum, 14. Ficus elastic, 15. Philodendron Majesty, 16. Philodendron domesticum, 17. Monstera adansonii, 18. Anthurium crystallinum, 19. Zamioculcas zamiifolia, 20. Gymnocalycium damsii variegata, 21. Syngonium podophyllum, 22. Gymnocalycium mihanovichii, 23. Philodendron wendlandii, 24. Chlorophytum comosum, 25. Caladium lindenii, 26. Fittonia albivenis, 27. Philodendron erubescens, 28. Cyperus alternifolius, 29. Aglaonema Schott, 30. Carina, 31, Rebecca, 32. Sarah. Images 1−29 were collected from local nurseries located in 24°22'26" N, 88°36'04" E and images 30−32 were adopted from Chen et al.^[1].

Foliage plants are a significant part of the industry due to their lower maintenance needs and their ability to effectively brighten up spaces. Foliage plants can be classified from various perspectives, such as water requirements, leaf size, plant toxicity, growth habits, and care levels needed (beginner-friendly, intermediate, or advanced). Additionally, foliage plants can be either variegated or non-variegated, with variegated ones typically receiving more attention and higher market value^[11]. The classification is based on the biological and ecological properties of houseplants, emphasizing their practical care requirements and suitability for specific indoor environments (Fig. 2).

Figure 2. 

Classification of houseplants. 1. Based on variegation, 2. based on leaf size, 3. based on growing structure, 4. based on water requirement, 5. based on care requirements, 6. based on toxicity.

Foliage plants are commonly kept indoors due to their low maintenance needs. However, optimal water, temperature, and fertilization are crucial for the growth and health of indoor plants. Most houseplants can tolerate temperatures below 10 °C and up to 30 °C, although growth typically stalls at 15 °C, with the ideal temperature for indoor foliage being around 21 °C. Temperature fluctuations, particularly a difference of 20 °C between day and night, can cause significant stress to indoor plants^[12].

Watering houseplants is an essential and sensitive step. Active growing plants, kept in comparatively hot weather with thin or large leaves require much water. When the plant media is hard on the surface or feels lighter, the plants require watering. Water can be sprayed over plants, simply poured into soil, or following the bottom watering process depending on the plant species. Hard water, containing high mineral levels can damage pH-sensitive plants^[12].

Light source is another vital factor for indoor plant growth. Decades ago, incandescent bulbs were commonly used, but these emit red and orange light, which is not ideal for photosynthesis. Today, LED lights are more prevalent; while they do not replace sunlight, they support sufficient photosynthesis for plant survival^[13]. Fluorescent lights are considered the best option for indoor plants, as they provide suitable wavelengths for photosynthesis without risking leaf burn. This type of light can also enhance the development of variegated plants, significantly increasing their value^[14].

Fertigation is essential for potted plants, as there are no alternative nutrient sources available. During the growing phase, applying fertilizers every 14 to 28 d is recommended, using lower doses more frequently rather than high concentrations infrequently^[15]. Indoor plants require both macronutrients—such as nitrogen, phosphorus, and potassium—and micronutrients for optimal growth^[12].

Propagation can be broadly classified into two categories, sexual propagation, and asexual propagation. Under asexual propagation they are propagated by leaf cuttings, stem cuttings, and division of suckers^[4]. Propagation of houseplants can be by different processes like propagation by seed, cutting, division, layering, water propagation, and micropropagation (Fig. 3).

Figure 3. 

Propagation techniques of houseplants. (a) Cutting propagation, (b) layering, (c) water propagation, (d) micropropagation.

Seed propagation

Seed propagation is common for cactus and some flowering plants. The foliage and succulent produce hardly any seeds to propagate^[16]. The succulents that can propagate through seeds are S. acrem, S. album, S. kamtschatticum, and S. reflexum including many others^[17]. Though many of foliage plants produce seeds but this is not as popular a propagation method. Hypoestes, Agrave, Cordyline, Dracaena, Nolina, Aocasia, Anthurium, Monstera, Philaodendron, Staphylium, Zamioculcas, and many others are reported as seed-producing foliage plants^[18].

Cutting propagation

Cutting propagation is one of the most convenient methods for foliage plants, often more cost-effective than tissue culture. A portion of the stem with a node can develop into a new plant under suitable conditions. The new plant is genetically identical to the mother plant. Cuttings can be categorized as cane, eye, leaf buds, or tip cuttings (Fig. 3a). This method is highly effective for succulents^[19] and is used for many houseplants, such as Pothos and Philodendron^[20].

Types of cuttings:

(1) Stem cuttings: common for many houseplants like Pothos and Philodendron^[20].

(2) Leaf cuttings: used for plants like African violets and begonias^[21].

(3) Root cuttings: less common but used for plants like snake plants^[22].

Advantages: faster growth compared to seeds, and clones of the parent plant^[20].

Disadvantages: some plants are difficult to propagate this way^[22].

Layering

Layering involves bending a stem to the ground or a pot of soil, covering part of it with soil, and waiting for roots to develop before severing it from the parent plant (Fig. 3b).

Types of layering:

(1) Air layering: common for larger houseplants like rubber plants and monstera^[21].

(2) Ground layering: less common indoors but used for vining plants^[20].

Advantages: high success rate, less stress on the parent plant^[22].

Disadvantages: slower process can be cumbersome for indoor settings^[20].

Water propagation

Water propagation is similar to cutting propagation where clean water is involved instead of soil or coco peat (Fig. 3c). This process is mainly a method of root formation but many foliage like lucky bamboo, philodendron, and pathos can easily propagate and grow in clear water. Water propagation is easy, cheap, and convenient for a commercial approach. The popular houseplant Ficus benjamina is difficult to propagate in soil but can be easily propagated in water^[23]. Dracaena sanderiana (common name lucky bamboo), may not only propagate in water but also can be grown on clear water due to it's aesthetic appeal^[24].

Advantages: high propagation success rate, genetic makeup is similar to the ex-plant^[20].

Disadvantages: in water propagation nutrients are limited so growth can stall and roots may rot with time^[25].

Propagation by division

Propagation by division involves dividing a plant containing plant roots or bulbs. It is the easiest method for plants that have bulbs or crowns^[26]. Houseplants like Zamioculcas zamiifolia, Aloe vera, Chlorophytum comosum, and Spathiphyllum can be propagated in this manner.

In vitro micropropagation (tissue culture)

In vitro propagation is the most effective method to grow large-scale healthy plants in a short period. This technique, also known as micropropagation, can be carried out in various ways, such as meristem culture, somatic embryogenesis, and micropropagation via thin cell layers. Although micropropagation is not as convenient as traditional propagation techniques due to high production costs and the need for specialized laboratory facilities, it is particularly useful for producing new or variegated indoor plants (Fig. 3d). Industrial orchid cultivation, for instance, has successfully employed micropropagation as the primary propagation technique, proving to be both successful and economically beneficial^[27].

Despite the challenges, micropropagation remains the most widely practiced method in the plant industry due to the high demand and price range of plants. However, successful micropropagation procedures used in industries are rarely documented as scientific discoveries due to business strategies and other issues.

The first successful micropropagation of Anthurium was reported in 1974^[28]. Subsequent reports have documented the micropropagation of several Anthurium varieties. Several indoor plants, such as Dracaena sanderiana^[29], and Paphiopedilum orchid^[30] have been successfully micropropagated. Micropropagation of Lacy Tree Philodendron was reported in 2020^[31]. Monstera acuminata Koch and Monstera deliciosa Liebm have been propagated in vitro recently^[32]. Very recently in vitro propagation of Philodendron erubescens 'Pink princess' has been successful and claimed to be suitable for large scale production^[33].

The practice of indoor plant micropropagation is increasing dramatically due to high market demand and its acceptability for maintaining variegation. However, maintaining aseptic conditions and selecting appropriate media components are crucial for successful micropropagation. Recent studies on developing micropropagation protocols for popular indoor plants are included here. Table 2 includes sterilization techniques, and Table 3 presents the culture media for several successful foliage plant tissue cultures with suitable media.

Variegated plants are characterized as plants possessing leaves with regular or irregular spots or patches. Patches are generated naturally or chemically, though plants with pathological infection, chlorophyll deficient lesions, or variegated areas outside of leaf blades are excluded from this group^[38]. Several research articles^[39] identify five anatomical categories of variegated plants: (1) Presence of non-green leaf areas due to chlorophyll deficiency. (2) Presence of intercellular air spaces just below the epidermis. (3) Specific morphology of adaxial epidermal cells. (4) Accumulation of non-photosynthetic pigments that conceal the green hue of leaves. (5) Presence of more epidermal cells and thicker outer tangential cell walls.

Additionally, variegation can be classified macroscopically; fishbone-shaped, blotched-shaped, V-shaped, spotted, striped, reticulate, and pinnate.

The main area of interest at present is understanding how plants can be rendered variegated. Variegation can occur naturally or be induced artificially. While natural variegation often stems from genetic factors and environmental conditions, artificial methods—including chemical treatments and light manipulation—can also create these patterns. This discussion examines both natural and induced variegation, highlighting recent horticultural techniques used to achieve and control these decorative effects (Fig. 4). Natural variegation occurs due to transposons, beneficial viruses, chimeras, gene expression manipulation, and controlled light exposure^[40,41]. Variegation can also serve as a defensive mechanism or help plants resist environmental stress. For instance, the variegated leaves of Arum italicum accommodate photosystem-II, which increases photosynthesis under low light conditions^[42]. Similarly, variegated leaves of Hydrophyllum virginianum protect against herbivory^[43].

Figure 4. 

Natural and chemical inducers of variegated houseplants.

In modern horticulture, plants are intentionally variegated through light adjustments, chemical mutagens, or physical mutations to enhance their aesthetic appeal and market values. Popular methods include gamma rays, ion beams, colchicine, and metabolic route alterations. Ionizing radiation, such as X-rays and gamma rays, can cause chromosome rearrangement, while ion beam radiation produces single or double-strand breaks^[44,45]. This mutation can cause shifting flower color in chrysanthemum and promote changes in chlorophyll production by carbon ion buildup^[46]. The natural and chemical inducers of variegation are shown in Fig. 4.

Currently, few strategies for inducing variegation in indoor plants have been explored. Selective breeding and targeted propagation have established key foliage plants like Aglaonema, Dieffenbachia, Dracaena, Epipremnum, Ficus, Hedera, Philodendron, and Syngonium^[47]. The latest trend focuses on developing propagated plants with induced variegation. Research by Taguchi shows that treatment with 4-methoxy-3,3'-dimethylbenzophenone can induce tiger stripe or partial leaf whitening variegation in plants such as Philodendron oxycardium, Spathiphyllum patinii, Musa spp, Anthurium, Cymbidium, and Dracaena surculosa. Additionally, 2,3,5-trichloro-4-hydroxypyridine induces tiger stripe variegation in Dracaena fragrans, while α-(2-naphthoxy) propionanilide induces similar variegation in Epiphyllum pumilum^[48].

Developing new plant cultivars can be approached through several innovative techniques (Fig. 5) beyond the random use of physical and chemical mutagens. These include isolating unique mutants, somaclonal variation, controlling gene expression, genetic rearrangement using transgenes, and editing metabolic pathways. For example, physical and chemical mutagens can induce leaf color changes, which can be maintained through tissue culture. These changes can result in albino, greenish-white, white emerald, light green, greenish-yellow, etiolation, yellow-green, and striped varieties, affecting chlorophyll, anthocyanin, and other pigment production^[49]. Treating Zamioculcas zamiifolia with colchicine can produce a dwarf variety with unusual black leaves, known as the black ZZ plant^[7]. Chlorophyll synthesis involves 15 steps, and mutations in early enzyme production genes can cause albino or yellow leaves. Mutations in genes encoding aminolevulinic acid dehydratase, porphobilinogen deaminase, and uroporphyrinogen III cosynthase, involved in photosynthesis can lead to albino or yellow leaf phenotypes. This type of mutation in genes is responsible for patches or stripes on leaves^[50]. In Populus canadensis, overexpression of the PtrMYB119 gene increases anthocyanin accumulation, leading to strong red pigmentation^[51]. Similarly, overexpression of Arabidopsis PAP1 induces high anthocyanin accumulation, resulting in dark purple leaves^[52]. In Setaria italica, the bHLH transcription factor PPLS1 controls purple pigmentation in the pulvinus and leaf sheath. The V shaped variegation of Trifolium repens is regulated by Rm, Rid, and Rl genes^[53]. Manipulating metabolic pathways by feeding selective precursors can induce desired traits. A study by Brugliera et al. showed that feeding delphindin precursor to Chrysanthemums can induce the desired violet color^[54]. Genes like Bo9g058630 coding dihydroflavonol 4-reductase (DFR) and Bo3g019080 coding shikimate O-hydroxycinnamoyltransferase (HCT) are studied in differentially expressed gene (DEG) approach and they affect anthocyanin, chlorophyll production in shades pink leaves, green-pink combined colored leaf. While transcription factors TT8, MYBL2, GATA21, GLK2, and RR1 are potential regulators of leaf color change in Brassica oleracea var. acephala^[55]. RT-PCR analysis of leaf variegation of E. aureum 'Golden Pothos' showed little expression differences of a marker gene, EaZIP between green and whitish plants or between green and whitish sectors of a variegated leaf^[56].

Figure 5. 

Proposed approach for developing new cultivars of houseplants.

Somaclonal variation is an important source for the cultivar development of houseplants. Somaclonal variation can be defined as the phenotypic variation found among the houseplants regenerated through the passage of tissue culture^[57]. It may occur during the plant's regeneration process through either organogenesis or somatic embryogenesis. In vitro culture houseplants generate somaclonal variants that can be novel and can be fixed through vegetative propagation. The variation includes morphological traits, response to biotic or abiotic factors, and production of specific compounds. The extent of somaclonal variation can be determined as the percentage of plants showing alternation of one or more defined characteristics. Such plants are called 'somaclones'^[57]. Plant tissue culture causes the wounding of explants, and it causes transposon activation^[58]. In vitro explant culture can result in cell dedifferentiation, induction, and differentiation. During this process, cells may reset the genome expression due to exogenous stress and not follow the same orderly sequence that is usually followed under natural conditions^[59]. Instead, the genome may be abnormally reprogrammed or decidedly restructured. This restructuring can give rise to wide ranges of altered phenotypes in the regenerated plants^[60,61]. As a result, a longer regeneration process will produce more somaclones. Table 4 represents the number of somaclonal variants released so far based on the information available from open access resources.

CRISPR-Cas is another promising tool for developing new ornamental plant varieties. This technology allows for the silencing, over-expression, or point mutation of specific genes responsible for desired traits. Although its use in ornamental plants is still limited, it has shown revolutionary changes in fruit, vegetables, and medicinal plants. Petunia hybrida is the first ornamental plant edited with CRISPR-Cas9, with many others in development^[7].

Houseplants have a significant impact on various aspects of life. They improve air quality by absorbing toxins and releasing oxygen, enhancing overall well-being. Houseplants also reduce stress and boost mood by creating a calming environment. Additionally, they can increase productivity and concentration, making them beneficial for both homes and workplaces. The presence of houseplants stimulates economic growth through increased sales in the gardening and home decor industries. In workplaces, they can reduce absenteeism and indirectly benefit businesses financially. Furthermore, houseplants may enhance property values by improving the aesthetic appeal of homes and offices.

Mental and physiological health

Humans have a long-standing connection with plants, and the practice of keeping indoor plants is ancient due to their mental and physiological health benefits. Over the past three decades, numerous studies have confirmed these benefits^[71]. Indoor plants create a soothing environment, improve air quality, and help alleviate respiratory and anxiety-related conditions. A Norwegian study of 385 office workers found that indoor plants positively impact stress management and productivity^[72]. In the USA, employees reported an improved quality of life, with men showing a better response to indoor plants^[73].

NASA's Clean Air Study highlighted the air-purifying abilities of plants like the spider plant (Chlorophytum comosum) and peace lily (Spathiphyllum). Research in Japan and the USA indicates that indoor plants enhance productivity, reduce anxiety, improve mood, and increase energy and concentration^[74,75]. Indoor plants are effective in managing anxiety and respiratory conditions, with foliage plants significantly helping symptoms related to mucous membrane neurophysiology^[76]. A study showed that hospital patients exposed to plants for just 10 min experienced higher pain tolerance, lower self-rated pain intensity, and reduced electrodermal activity^[77]. Patients recovering from surgeries with plants in their rooms had faster recovery, lower blood pressure, reduced fatigue, and less need for analgesics^[78].

While the benefits of indoor plants are evident, further homogeneous research is needed for definitive conclusions. Existing studies, however, indicate that indoor plants positively affect human physical and mental health.

Improvement indoor air quality

Improving indoor air quality is essential, especially in spaces where volatile organic compounds (VOCs) from paints and furnishings can cause respiratory issues, irritation, and allergies, particularly in children^[3]. Research has shown that indoor plants can reduce organic pollutants like benzene, toluene, ethylene, formaldehyde, xylene, and harmful compounds such as carbon monoxide, ozone, aldehydes, and ketones. Key species like Sansevieria trifasciata, Chlorophytum comosum, and Epipremnum aureum are effective in this process^[79].

Indoor plants can decrease VOC concentrations by around 35%, though some ornamental plants may emit VOCs themselves^[76,80]. Species such as Hedera helix, Chrysanthemum morifolium, Dieffenbachia compacta, and Epipremnum aureum can remove up to 96% of formaldehyde within 24 h^[81]. Similarly, Pelargonium domesticum, Ficus elastica, Chlorophytum comosum, and Kalanchoe blossfeldiana can eliminate 85%−95% of benzene within the same period^[82]. Azalea indica can remove 95% of toluene within 72 h^[83], while D. deremensis and O. microdasys can eliminate 95% of toluene, xylene, and ethylbenzene within 48 h^[79]. Furthermore, they have shown the capability to clear 95% of ozone within 2 h^[84]. However, recent studies suggest that achieving substantial purification may require 10 to 1,000 plants per square meter^[85].

Sustainability and environmental considerations

As environmental awareness grows, sustainability is becoming central to houseplant propagation. The industry faces scrutiny over its environmental footprint, especially regarding non-renewable resources like peat moss and carbon emissions from plant transport^[86]. Future trends emphasize sustainability, with techniques like aeroponics showing success in cultivating varieties such as Ficus, Philodendron, and Dracaena^[87]. Innovations like vertical farming, green walls, and green roofs enhance urban aesthetics and promote a healthy atmosphere. These solutions are increasingly integrated with advanced technologies, including IoT and robotics, to streamline maintenance and irrigation, furthering their environmental benefits^[88,89].

Social and economic importance

Houseplants offer significant social and economic benefits. Aesthetically, they enhance the appeal of homes and workplaces, fostering inviting environments that encourage social interaction and community building. Economically, the houseplant industry has seen substantial growth, fueled by rising interest in home gardening and indoor plants. In recent years, rare varieties have driven this market to new heights. For example, Philodendron Minima (mini Monstera) sold for USD${\$}$8,150 in 2020, and a variegated Monstera deliciosa fetched USD${\$}$5,000 on Trade Me. In 2022, a variegated Monstera adansonii was sold for USD${\$}$38,000 on eBay due to limited supply and high demand (www.gardenista.com).

Prices for houseplants vary based on size, demand, and availability. Popular species like the Monstera Thai Constellation are priced between USD${\$}$99 and USD${\$}$140 due to their unique variegation. The Monstera deliciosa ranges from USD${\$}$48 to USD${\$}$228, influenced by size and variegation. Zamioculcas zamiifolia is priced from USD${\$}$48 to USD${\$}$198, while the Philodendron White Wizard and Pink Princess are around USD${\$}$98. More affordable options include the Bird's Nest Fern (USD${\$}$48−USD${\$}$78), Apoballis lavallaei (USD${\$}$78), and Aglaonema pictum Tricolor (USD${\$}$98−USD${\$}$128). The Stromanthe Triostar, with a price range of USD${\$}$58−USD${\$}$78, offers vibrant foliage at moderate cost. Budget-friendly choices like Devil's Ivy (USD${\$}$41−USD${\$}$51) and red Anthurium (USD${\$}$64) are popular among beginners and those seeking cost-effective greenery.

The worldwide market for houseplants is witnessing significant growth due to their appeal for decorative purposes, the wide variety of available species, aesthetic value, ability to create refreshing and soothing environments, and the belief in their air-purifying properties. Additionally, houseplants add a new dimension to interior decor and enhance the visual appeal of living spaces. The monetary value of indoor plants has experienced a substantial increase since the 1980s, with considerable potential for further growth in both domestic and international markets^[90]. Leading the forefront of indoor plant production are companies such as DÜMMEN ORANGE (USA), Syngenta (Switzerland), Beekenkamp Group (Netherlands), Hofland Flowering Plants (Netherlands), SAKATA (USA), DUTCH FLOWER GROUP (Netherlands), MARGINPAR BV (Netherlands), Walter Bloom Plants BV (Netherlands), Selecta Klemm, Double H Nurseries Ltd (Germany), ARCANGELI GIOVANNI (Italy), KP Holland (Netherlands), and Ball Horticultural Company (USA) (Indoor Plants Market By 2031)^[91].

The indoor plant industry amounted to a business of USD${\$}$16.2 billion by 2022 solely in developed countries, a significant leap from the mere USD${\$}$13 million in 1949 and USD${\$}$574 previously (Indoor Plants Market Size, Share, Trends | Forecast, 2032)^[92]. In the early 20^th century, successful micropropagation of 156 species was achieved, with the Netherlands contributing 33%, Japan 24%, Italy 11%, and Thailand 10%, indicating a global effort to commercially produce ornamental plants^[93]. Now the Netherlands is the leading exporter of micro-propagated plants, contributing 59% of global exports. Following the Netherlands are Italy with 16%, Colombia with 10%, Israel with 4%, Spain with 2%, Kenya with 1%, and other countries collectively making up 18% (Fig. 6). According to OEC world report 2022 the houseplant market has been taken over by Netherlands, Canada, USA, China and some others country (oec.world).

Figure 6. 

Major houseplant exporter countries worldwide.

Houseplants have surged in popularity over the past decade, becoming a staple in homes, offices, and public spaces. This trend has not only transformed interior design but also spurred a growing interest in plant care and propagation. The future of houseplant propagation holds exciting potential, driven by advancements in technology, shifts in consumer preferences, and increasing awareness of the benefits of indoor greenery. The future prospects of houseplant propagation are explored by considering factors such as technological innovations, sustainability, and market trends.

The future of houseplant propagation is likely to see significant advancements in biotechnology. Tissue culture, also known as micropropagation, involves growing plants from small tissue samples in sterile, controlled environments. This method allows for the rapid production of large numbers of identical plants, ensuring uniformity and quality^[9]. Advances in gene editing and nanotechnology are significantly influencing the ornamental plant industry, enhancing the efficiency and outcomes of micropropagation^[94]. Current trends in micropropagation focus on optimizing tissue culture media by incorporating various plant growth stimulators, biostimulants, and light spectra^[37,95,96]. The use of light spectra, a novel approach introduced in 2023, has shown promise in embryo production for terrestrial orchids^[96]. AI models are increasingly applied to improve various stages of tissue culture, including in vitro sterilization, callus induction, shoot multiplication, and acclimatization. By analyzing a wide range of data—such as binary inputs (e.g., embryogenic vs non-embryogenic callus), discrete variables (e.g., number of roots and shoots), continuous variables (e.g., shoot length), time-series data, fuzzy inputs (e.g., callus color), and categorical variables (e.g., types of phytohormones)—AI facilitates a comprehensive understanding of the interactions among these variables^[97]. Looking ahead, smart greenhouse technology promises to further enhance production efficiency by optimizing water supply, temperature, humidity, and lighting conditions for plants^[98].

Genetic engineering tools such as CRISPR-Cas9 hold revolutionary potential by enabling precise gene editing to express desired traits. Manipulating genes responsible for color pigments can produce plants with uniquely vibrant hues, as seen experimentally in colorful Caladium varieties^[99]. Furthermore, tissue culture technology offers substantial production scalability in short periods, essential for meeting increasing market demands globally.

Automation and artificial intelligence could revolutionize houseplant propagation by optimizing growing conditions and automating routine tasks. This could lead to higher success rates and lower labor costs^[100].

The future of houseplant propagation is bright, driven by technological advancements, a focus on sustainability, and evolving consumer preferences. As the industry evolves, we can expect more accessible and innovative propagation methods, environmentally friendly practices, and a diverse market catering to a wide range of tastes and needs. Houseplants will continue to play a vital role in our lives, offering beauty, health benefits, and a connection to nature. The propagation of these plants, whether for personal enjoyment or commercial purposes, will be a dynamic and thriving field, reflecting broader trends in technology, sustainability, and lifestyle.