How to Grow Houseplants Sustainably

There’s nothing like an army of houseplants to brighten up a home. Interacting with indoor plants is proven to help with stress, help purify the air, and bring beauty and nature into our daily lives. But, a houseplant habit isn’t necessarily good for the environment. Here’s how to keep your plants healthy and happy without harming the planet.

Buy Responsibly

Before taking a new plant home, consider its roots. Search for shops in your area that source from ethical growers that follow organic practices. Many plants – especially tropical species – are also grown and shipped long distances to reach store shelves. Purchase from nearby nurseries (or plant stores that source from them), as well as nurseries that grow plants themselves rather than companies that remove them from wild habitats. Better yet, shop secondhand plants that can be picked up locally from online platforms like Facebook Marketplace, where you’ll score much better deals on mature plants.

Online plant retailers have grown in popularity, especially as the pandemic confined us to our homes. While convenient, shopping for live plants online comes with an environmental price tag: expedited shipping via plane is usually needed to transport plants before they wither, and the necessary packaging to keep delicate plants safe in transit leads to much more plastic waste. Before ordering online, take a trip to your local plant shop – many of whom offer local deliveries, if needed – to see if they have what you’re looking for.

Buy Small, and Propagate

For every plant on that store shelf, many resources were needed to raise and transport it: electricity for grow lights, fuel for transportation, plastic for packaging, water, and fertilizers. Instead of buying an entirely new plant that required all of these inputs during their nursery days, cut a piece from a friend’s and or family member’s plant and grow an entirely new plant in your own home. If you can’t track down a clipping of your dream plant, purchase it as a smaller plant rather than a larger one, which required less space and energy to transport and support.

Avoid Plastic Pots

Store-bought plants usually come in plastic nursery pots, and most species want to get out of that impermeable plastic as quickly as possible. Like a lot of plastic, plant pots are very hard to recycle, especially given that many are made from largely unrecyclable black plastic. Many plant stores will reuse the plastic pots at the shop, or will send them back to the nursery – ask your plant store of choice what their practices are, and compare local options. If they use biodegradable pots, even better.

Once the plant is out of its original plastic – which sometimes can’t be avoided – you’ll need to transfer it to an adequately-sized pot. Luckily, there are lots of affordable options for attractive, plastic-free pots. Terracotta clay pots offer better aeration for plants than plastic, and if they break, the pieces can be used for additional drainage in the bottom of the pot. Or, check out yard sales or thrift stores for used pots. Some garden centers even have clearance sections for pots with minor damage, like small chips or cracks that would otherwise be headed for the dumpster.

For craftier plant parents, add a cute statement piece to your home by upcycling other materials to make your own pots – like tin cans, old bowls or mugs, etc. – keeping in mind the moisture needs of the specific plant (stone and clay allow for better drainage), and always cut or drill a drainage hole in the bottom for water to flow through.

Avoid Grow Lights

Grow lights are an option for indoor plant-rearing in homes without much natural light, but, like all appliances, they require energy. To be effective and deliver the benefits of real sun exposure, most grow lights need to be left on for about 12 hours, which equates to a not-insignificant amount of energy usage.

Ultimately, it’s best to avoid buying plants that won’t do well in the conditions you can provide. Place plants where they get the necessary amount of light without additional lamps. Otherwise, stick to plants that require only minimal light, like cast iron plants, snake plants, and pothos. If you do need grow lights, or already have plants that require the extra light, get a timer that will switch the light on and off after the appropriate time, especially when you’re away from home.

Reuse Water

Watering plants (especially if your collection is very lush) can use up a lot of water. Since most plants don’t need filtered water, you can reuse water from other means to keep them hydrated and happy, such as the water used to rinse produce. On watering day, check the fridge for any fruits or veggies that need to be washed. Wash in a colander over a large pot or bowl, using the collected water to pour into plants.

Collecting rainwater for plants also involves no special plumbing, and very little time or effort – and, as a bonus, rainwater is actually better for some plants, as it hasn’t been chemically treated with chlorine or other additives like most tap water. Research which system works best for you and your space: that could mean a bucket on the fire escape if it’s going to rain the night before watering day, or installing a downspout on the roof that flows into a barrel covered with a screen to filter out debris, and a small spigot on the bottom to dispense water.

If you live in an area that frequently experiences water shortages or drought, consider adding plants with low water requirements to your collection, such as snake plants, cacti, and succulents.

Avoid Peat Moss

Many planters add peat moss to their soil mixes: a popular material for its moisture- and oxygen-retention properties. Peat moss is plant matter that has decomposed anaerobically (without the presence of oxygen), and while it’s technically a renewable resource, it takes centuries to completely regrow. Peat bogs are complex ecosystems that many species rely on, but have been subject to over-harvesting in countries where it covers large areas, like Ireland, Scotland, and Canada. Among other hydrological and ecosystem services, peat bogs are also huge carbon sinks, taking carbon dioxide out of the atmosphere and playing a part in reversing climate change. For peat moss alternatives, try compost, coconut coir (made from fibers of coconut husks), wood products like sawdust and bark, rice hulls (the discarded skin of rice grains), and pine needles.  

Use Organic Fertilizers

Indoor plants depend entirely on their plant parents for nutrients, but many synthetic fertilizers contain hazardous chemicals and can be harsh on plants. Organic and natural fertilizers are made of nontoxic materials and contain different concentrations of the three major macronutrients: nitrogen, phosphorus, and potassium. Fish fertilizer (sometimes called fish emulsion) is a popular organic fertilizing solution that’s high in nitrogen, phosphorus, and potassium – or, take a scoop of your own aquarium water, which is full of natural nutrients from fish waste and fish foods. Blood meal, alfalfa, cottonseed meal, rock phosphate, bone meal, kelp, and granite meal are alternative organic fertilizers that can be mixed and added to your plants’ soil based on their nutrient needs.

Compost is in ideal, nutrient-rich plant fertilizer; make your own compost at home with food scraps, or purchase from local garden stores or compost centers. Or, simply add kitchen scraps to the soil and let them work their magic. Try eggshells for calcium, banana peels for nitrogen and phosphorus, coffee grounds for nitrogen and better drainage, and green tea or apple cider vinegar for plants that like acidity, like begonias and African violets.

Use Natural Pesticides

When you spot pests or fungus on a plant, it should be dealt with quickly to prevent spreading to other pots or causing further damage to the plant – but, like fertilizers, many conventional pesticides contain toxic chemicals, like copper and sulfur. Try natural fungicide and insecticide instead. Many organic pest-prevention products are available at stores; consult with a retail associate about ingredients and research the right products for your plants before purchasing.

It’s easy to make your own natural pesticides at home, too, but be sure to spot test any remedy – homemade or store bought – to see how your plant responds before proceeding. Derived from seeds of the neem tree, neem oil is among the most popular of organic pesticides, and routine applications prevent bugs from laying eggs or feeding.

A simple soapy spray helps dehydrate aphids, spider mites, and other pests. Simply mix 2 tablespoons of mild liquid dish soap with a gallon of water, then spray directly on the plant, including the undersides of leaves. Baking soda is another effective treatment for black spot and powdery mildew, and is nontoxic for pets and humans alike. Combine 1 teaspoon of baking soda per quart of water, adding liquid soap to help the solution stick to the leaves if desired, then spray. Garlic is also toxic to many insects, and a solution made from crushed cloves steeped overnight in boiling water will do the trick.