Tropical houseplants have increased in popularity as a U.S consumer good, with houseplant sales increasing by 50% simply in the last three years.
Potting media is a necessary, complementary good to houseplants: any houseplant owner knows that having some potting soil on hand enables you to repot your growing plants at a moment’s notice, or refresh soil that has been depleted of its nutrients.
Many indoor plants, such as Philodendron, Epipremnum, and Monstera, are epiphytic, which means that they grow best on other plants, such as trees. Their roots have evolved to grow on bark amidst the open-air; and thus, they require lots of oxygen to stay healthy. Traditional, soil-based potting media (think the stuff you can buy at Lowe’s) suffocates these fragile roots by depriving them of the oxygen they need, resulting in high demand for soilless media by houseplant enthusiasts.
The most popular non-soil based media is peat moss, which is a form of decayed sphagnum moss derived from peat bogs. This media was traditionally used in horticulture for decades, but recent concern over the depletion of peat bogs has driven a hunt for a more sustainable alternative. Peat bogs, are characterized by the slow decay of plant matter that can only take place over millennia. It can take up to 10 years for one square centimeter of peat moss to form. But peat moss has some qualities that horticulturalists consider to be indispensable–it can hold many times its weight in water without making the soil soggy. It contains copious amounts of nitrogen and phosphorous–essential nutrients to plants.
A popular alternative to peat moss that has arisen in recent years is coco coir, a byproduct of the coconut industry. The “coir” consists of ground up coconut husks. While coir degrades more rapidly than peat does and contains less essential nutrients, it is able to hold on to many times its weight in water while maintaining aeration in the soil. Also, it is extremely cheap to produce, as it is essentially a waste product that has been repurposed and marketed to the horticulture industry.
Coco coir has earned quite a bit of buzz among houseplant growers. Plant “influencers” and growing experts are encouraging its use as a peat moss alternative. What makes the material even more appealing to consumers is that the material would have otherwise gone to waste.
What’s the issue? Well, in order for coconut coir to be available on the market in the quantities demanded, coconut tree plantations must occupy large swathes of land. Where do coconut trees grow best? In the tropics, and especially on the coast. For this reason, coconut production (often in the form of monocrops) is concentrated in Indonesia, the Philippines, Fiji, India, and other tropical, coastal environments.
These environments also happen to coincide with the native range of many of the epiphytic, tropical plants commonly grown by houseplant enthusiasts. These plants require media like coco coir to thrive indoors, and yet the production of this media directly contributes to the loss of these plants’ habitat.
I am not asserting that the use of peat moss in potting media is better, and that we should return to that. However, it is worth taking pause to consider that demand for a sustainable alternative to peat moss has landed on a material that contributes towards the destruction of these plants’ habitats. No sustainable alternative is perfect, and economic outcomes often conflict with environmental impacts. This case is particularly unsettling, as the production of a complement of a good undermines the vitality of the good itself.