Being a plant parent is harder than I thought. I’ve killed a snake plant (the one they say is virtually indestructible), overwatered a succulent, given my monstera root rot, and two of my peace lilies have died of unknown causes (thankfully the third is thriving).

One thing I’ve learned: while a lot of care focuses on water and sunlight, soil is an important factor, too. It gives the roots something to anchor to, holds water, helps regulate temperature, and supplies nutrients to keep plants healthy.

Horticulturalists Dominic Hooghuis and Duncan Hilder, owners of store The Plant Runner, want to help you take care of your soil, and in turn, take better care of your plants. That’s why they’ve added a Soil and Microbe Booster to their range of products.

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“An indoor plant that isn’t getting a complete fertiliser is like a person living on a diet of bread,” Hooghuis and Hilder tell Broadsheet. “They may be getting enough sustenance to keep them going but they are definitely not getting a balanced diet that will allow them to be all they can be.”

The fertiliser uses a mix of biochar and frass: biochar is a charcoal-like substance that helps with plant resilience (meaning it can survive long dry spells or overwatering), while frass is full of trace nutrients such as iron, copper and zinc. Chitin (insect exoskeletons used in frass) also help fight pathogens such as the ones that cause root rot.

“Essentially, it will breathe new life into your potting mixes by adding millions (over 240 million per gram) of beneficial microbes to your soil while boosting its nutrient and water holding capacity,” says the duo. “Fertilising your indoor plants is important because, unlike their cousins outside, your indoor plants are relying on you to provide them with the nutrients they need.”

Spring is when plants undergo the most growth, so they’ll be hungrier than usual. You’ll just need to sprinkle one or two teaspoons of the booster as a top dressing, then you won’t have to worry about it again for three months.

In addition to the Soil and Microbe Booster, The Plant Runner also creates its own indoor plant food, neem oil to give leaves a shine, and different potting mixes for cacti and succulents, indoor plants and aroids or tropical houseplants. Its new The Plant Runner Booster Kit includes the soil booster, neem oil and indoor plant food as a bundle.

The online plant care and lifestyle hub also carries a range of tools and products from different brands that help with different aspects of plant care, from watering and propagation to plant stakes and terrariums.

One per cent of all sales each month will be donated to an environmental non-profit, and The Plant Runner avoids single-use plastic packaging where possible – that means refillable glass bottles, recyclable paper tape and eco-friendly packing peanuts. The soil booster is also carbon-negative – every kilogram of frass produce offsets more than seven kilograms of carbon dioxide emissions.

The Plant Runner’s Soil & Microbe Booster costs $19 for 500 millilitres and is available now.