Credit: G Smith/Adobe Stock/Creative Market
How green is your Pinterest-perfect plant collection?
From lush, temperamental fiddle-leaf figs to laidback snake plants, indoor houseplants have become ubiquitous in the homes of many millennials and Gen Z -- particularly as their care became a soothing and serotonin-boosting hobby early in the pandemic.
New plant parents (including this writer) caused a spike in Google searches for popular flora such as pothos and prayer plants in early 2020, while seasoned caretakers offered tips for newbies on social media platforms like TikTok -- the hashtag #plantsoftiktok, for instance, has amassed over 6 billion views to date. Creating Instagrammable oases at home has become fast and easy, with home delivery sites such as The Sill and Bloomscape offering up alternatives to local shops.
But just how green is your greenery? It seems logical that more plants should be beneficial for the environment -- after all, they produce the oxygen we breathe. But recent research has shown that houseplants don't do as much in terms of improving air quality as initially believed. And they do have a toll on the planet, belied by their eco-friendly appearance.
Though it is challenging to quantify the environmental impact of indoor plants -- outdoor gardening, cut flowers and potted flowers are often grouped together with houseplants in studies on the horticulture business -- behind your local plant shop or e-tailer is a multi-billion-dollar industry that requires a massive amount of resources for growing and transporting greenery to reach your home. In the US alone, there are more than 2,300 indoor plant growers and sales were worth $691 million in 2019, according to a census report by the United States Department of Agriculture.
"Growing indoor foliage plants is a highly intensive process," said Dr. Loren R. Oki, a specialist in environmental horticulture at the University of California, Davis and co-director at the University of California Nursery and Floriculture Alliance. "There's high plant densities, there's fast turnovers (between growing and shipping plants). It's a really complex system...They require a lot of resources like energy, labor, water, (and) fertilizers," as well as the potting mix.
The hidden costs
Maintaining an indoor garden does have therapeutic and wellness benefits -- both indoor and outdoor gardening can ease stress, sharpen attention and help bring some much-needed green into urban environments. But horticulturist Missy Bidwell, who manages the greenhouse at Cornell Botanic Gardens in New York, also said it's important to be mindful of all the resources required to grow and maintain your houseplants, and to try and strike a balance. "When you stop and think about all of the inputs, you have to (consider) the outputs -- do they have a bigger advantage? Do they have a bigger impact on your life?"
In recent years, the horticulture industry has made strides in areas like energy-efficient greenhouses and improvements in water applications, but collective and urgent environmental impacts remain.
Water use further strains drought-prone areas, while nitrates from fertilizers have contaminated Chesapeake Bay, the largest estuary in the US, as well as California's drinking water, according to a 2012 report from UC Davis. Nitrous oxide is also emitted from these fertilizers -- a greenhouse gas that warms the atmosphere nearly 300 times more than carbon dioxide.
Pesticides are necessary in the industry, Oki points out, because "indoor plants and other nursery products are aesthetic products," he said. "They need to be perfect. If the plant has a brown leaf on it, people won't buy it. So there's the pressures of the consumer that growers also have to have to meet as well."
Then there's the potting mix your plants grow in. This is most often made up of peat moss thanks to its ability to retain moisture and nutrients. But, beyond harvesting, the world's peatlands are being depleted rapidly because of fires and development, making its use in horticulture particularly fraught. Peat protects the environment with its prodigious ability to absorb and store carbon -- damaged peat bogs do the opposite, emitting at least 2 billion tonnes of carbon dioxide annually, according to Nature.
And waste is an issue as well -- as with many industries, the horticulture sector has a serious single-use plastic problem. "Plastics are in everything that we do, from the pots to the bags of soil (to the) plastic tags, plastic sleeves," Bidwell said.
Take the petroleum-based plastic pots your houseplants arrive in. According to the USDA, large growers and nurseries use tens of millions of plastic pots in a single season. They are not recyclable in many places, and 98% wind up in landfills. In 2009, the USDA calculated that the container crop industry had produced 4 billion units, equalling 1.66 billion pounds of plastic.
"That piece of nature is wrapped in one of the most toxic materials for nature," said Andreas Szankay, a plant-shop owner in Brooklyn. "It doesn't really have to be that way."
The alternative is biodegradable pots, which Szankay and his wife Stephanie aim to popularize with their shop, Pollyn. They replant all their nursery plants into bio-pots, which are made of materials including coconut fiber, cow manure, and paper pulp.
Bio-pots keep plants healthier because "they allow for more air and water exchange," Andreas explained, and can help fertilize a plant's roots, depending on the material. They are easily found through Amazon or Home Depot, and Szankay hopes the nurseries who supply the plants will begin to use them, since they arrive at shops already potted.
In the scheme of things, your houseplant collection likely has much less of an environmental toll than what's in your closet or your fridge. And, like with the food and fashion industries, it may feel like an individual adopting sustainable practices is barely chipping away at a much larger problem that requires the biggest players to lead the way. But there are decisions you can make if you want a more sustainable indoor garden.
The first thing you can do is consider your own 'plant miles' when adding new additions to your collection, according to Bidwell.
Buying locally helps, "so that you're not using fuel emissions and things like that to procure your plants," she said. But you can also use clippings to create new plants -- a process called propagation -- with a little help from the internet. "Can you do plant swaps and can you share with neighbors," Bidwell suggested, "especially with some of the houseplants that are super easy to propagate?"
If you do make purchases online, do your research into where the plants are coming from. Companies like Bloomscape in Detroit and Rooted in New York, for instance, ship straight from the greenhouse, reducing your plant's journey by cutting out the shop.
To avoid using peat, users on TikTok recommend alternatives such as the fibrous coconut coir and the carbon-ash residue known as biochar -- both of which have been studied as viable alternatives.
But the best thing you can do is be mindful about the plants you own. Research whether or not you have the conditions (and the motivation) to keep finicky plants happy, and opt for a less-demanding resident if not. According to a recent report by Business Insider, Americans kill nearly half of the houseplants they take home, and plant deaths in supply chains and shops have been exacerbated by recent demand. Social media trends have also made rare plants such as white variegated monsteras or pink philodendron princesses highly coveted, but just because you can find a plant on Etsy doesn't mean you should impulse buy it. Focusing on water-efficient, low-light plants will make caring for your own collection easier, and will create less demand from growers to supply high-maintenance varieties.
Not everyone is a perfect plant parent (again, like this writer), but it's wise to rehome any you can't take care of, and there are options if a plant appears to be discolored, wilting and stubbornly determined to die. YouTube and TikTok videos provide an unending number of tutorials for how to rescue your collection from pests or overwatering -- in one viral video, TikTok user @the.plant.baddie gives helpful tips on anxiety-causing root rot, set against a soothing soundtrack of lo-fi beats. You can also learn when and how to repot, or how to propagate healthy trimmings to create an entirely new plant. (Just be sure to compost whatever you can't save.)
"Being a good steward of your plants is really important," Bidwell said. "Bringing (home) living beings is important, and you need to care for them."