Guide to Sustainable Indoor Plants - Part 3: Nutrients

So far, we have covered Soil and Water in this series on growing indoor plants more sustainably. Sadly, many of our standard practices are damaging to the environment, and ‘feeding’ out plants is no exception. It can easily be the most harmful of our practices.

Home growers use more pesticides and fertilizers per acre than industrial farming. While most of that is from outdoor gardeners, indoor plants often get more fertilizer than needed. Worst still is the obscene length growers go to eradicate pests. We will cover this in an upcoming blog in the series but just because your pesticide is organic does not mean it is safe or environmentally friendly, regardless of what it says on the bottle.

But for now, we will turn our attention to nutrients, a.k.a. fertilizers, a.k.a. plant food a.k.a. plant minerals. Like many terms in the plant hobby, these each have specific meanings that differ slightly from each other. Some are even inaccurate, such as plant food. But truth be told they are often used interchangeably by the casual grower and thus they have, for many people, come to mean the same thing. It’s that little boost we give to our plants to help them stay happy and healthy.

If you’re saying to yourself “I’ve never given my plants fertilizer and they seem to be doing fine” you might begin to see the problem.

How much of your plant’s growth is fueled by your fertilizer of choice? How effective is it? How essential is it? How can you ensure you are adding enough but not too much?

Many of these answers will change depending on the specific plant as each one has unique requirements when it comes to micro and macro-nutrients.

If you give your plants a ‘one size fits all’ regimen then you are probably underfeeding some and overfeeding others. Frankly, it is difficult to dial in the exact amounts of nutrients required and so most home growers (who fertilize) tend to overdo it, just in case. “I mean it is organic after all so it should be fine.”

No. Just, no. Regardless of whether it is organic it still came in a bottle shipped from far away. The excessive nutrients that get washed away go into and pollute our waterways. Organic is certainly a better option than synthetic as far as an initial energy requirement is concerned. But better doesn’t mean good. It just means not as bad. But it’s still not a sustainable alternative. It’s just a less damaging alternative.

One of the best things you can do to change this is to start making your nutrients at home. The quality of the product will be less particularly at first, and it will take time to get it going but home-made plant nutrients can easily be made using household waste.

Instead of creating more waste to support our plant-growing habit, we reduce our waste by indulging in the hobby. The most common methods for doing this usually involve some form of compost. Be it worm compost, bokashi, hot, or cold composting, or some form of turning your organic waste materials into plant food.

Hot composting is one of the fastest and most effective methods though it also takes up the most space and time. Bokashi and worm composting can be done indoors and in relatively small areas, but it will be difficult to make enough to feed all your plants if you have a large collection but a small space for composting.

There are other things you can do, such as create a Jadam Liquid Fertilizer (JLM). This requires soaking plant materials (usually nutrient-dense weeds) in water for a few weeks and then using the solution as a concentrated fertilizer. This works quite well and can be done in just a small bucket, but it stinks like death so it’s not for the faint of heart.

If it doesn’t stink, then it isn’t working. If you soak your banana peels and eggshells in water, they aren’t likely to do much unless they become a stinking rotting mess, but most “hacks” have you avoid this part because it is gross. The problem is it is essential in a liquid soak.

Generally, plants can’t eat organic matter. They need microorganisms to break down organic matter into basic chemical compounds that are water-soluble. It is the microbes and the breakdown of organic matter that are responsible for foul odor. If they are not present then the breaking down process, essential for making plant nutrients, is not taking place.

The reason good compost doesn’t smell is that it does. Good compost smells amazing for the exact reason JLM smells so bad. It is just different microbes that are breaking down the organic matter. In a liquid soak the good-smelling microbes won’t be present in large enough numbers to effectively break down organic matter. But in the low-oxygen environment of water that has sat with rotting plant matter is the perfect place for foul-smelling bacteria to thrive.

I recommend taking a good look at your space to see what you have the space, time, energy, and nostrils for. I want to encourage you to start to reduce and possibly eliminate your use of commercially available fertilizers regardless of their ‘organic’ status. And to start using your waste for your plants.

Getting into sustainable indoor plants?

Don’t forget to check Part 1: Soil, Part 2: Water & Part 4: Pest Management.

Still want to know more?

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