Compost is a highly beneficial soil amendment that enhances soil structure and health by introducing organic matter. While creating compost can take anywhere from one month to over a year, there are options for those with limited space or time. Some kitchen scraps can be used directly in the garden with minimal preparation.
Why use kitchen scraps in the garden?
In 2019, the EPA estimated that 66 million tons of food waste were generated in the food retail, food service, and residential sectors, with about 60 percent of this waste ending up in landfills. While home kitchen scraps may only account for a portion of this waste, reusing these scraps in sustainable gardening is an effective way to reduce waste and improve garden health. By repurposing common kitchen leftovers such as eggshells, coffee grounds, banana peels, and orange peels, gardeners can enrich their soil with nutrients and promote the growth of vigorous, healthy plants, all while being environmentally conscious.
1. Eggshells
Image: Debbie Wolfe/Popular Science
Image: Debbie Wolfe/Popular Science
Eggshells, often discarded as waste, have multiple benefits for both gardens and bird care. As an avian dietary supplement, finely crushed and sterilized eggshells can be a vital source of calcium for birds, especially during their nesting season. To render eggshells safe and pathogen-free, they should be rinsed and baked at 250° F for 10 minutes before being added to bird feeders. This offers crucial nutrients to seed-eating birds. Additionally, crushed eggshells can serve as an effective pest deterrent; laying a barrier around plants can help prevent damage from slugs and snails. For more severe infestations, combining them with diatomaceous earth may provide enhanced protection.
Contrary to some beliefs, eggshells in the garden do not prevent blossom-end rot in tomatoes and other sensitive plants, but they do contribute positively to soil health. Adding crushed or ground eggshells to the soil improves its texture and gradually introduces slow-release calcium. Although they may not stop certain plant diseases, their use as a soil amendment is beneficial for general garden upkeep, enhancing the overall mineral content and structure of the soil.
2. Coffee grounds
Coffee grounds, often regarded as mere waste, are actually a boon for eco-friendly practices, serving multiple roles in garden care. As a mild, organic fertilizer, coffee grounds contain essential minerals such as nitrogen, potassium, and phosphorus, which enhance soil fertility and support plant health, albeit not as a standalone treatment. Their use should be balanced with other fertilizing methods to ensure long-term soil health.
Additionally, coffee grounds act as a potent soil conditioner. When integrated into the upper layers of garden soil, they enrich the soil with nitrogen, thereby improving its structure and increasing the soil’s ability to retain water and air, promoting healthier plant growth.
Furthermore, coffee grounds prove to be an effective compost booster. Their high nitrogen content aids in accelerating the decomposition process within compost piles, enriching the resulting compost with valuable nutrients essential for plant growth. For optimal composting results, it is recommended to mix coffee grounds with carbon-rich materials like leaves, straw, or paper to create a balanced environment that facilitates efficient breakdown and nutrient release. This multifaceted utility makes used coffee grounds a prized resource for gardeners aiming to adopt more sustainable practices.
3. Banana peels
Banana peels are a rich source of potassium, which is crucial for plant growth and health, especially in promoting the development of flowers and fruits. This potassium is released slowly into the soil, providing a steady supply of this essential nutrient as the peels decompose. Additionally, the decomposition of banana peels may attract beneficial worms that further aerate the soil and enhance its structure, facilitating easier root growth and nutrient absorption.
An alternative method involves using banana peels in a water-based fertilizer by macerating the peels in water for a week. This ‘banana water’ provides a nutrient-rich solution that helps boost plant resilience and growth by supplying significant amounts of potassium, an essential plant macronutrient. It is important to use banana peels in moderation around plants to avoid attracting larger pests and to maintain the balance of nutrients without overwhelming the site with organic waste.
4. Orange peels
Orange peels can be used to deter feral cats from using gardens as litter boxes. These peels repel cats and serve as a natural deterrent against common garden pests such as aphids and ants. The strong citrus scent and limonene in the peels make them unappealing to many pests, establishing them as an effective, organic method for maintaining garden health. As the orange peels decompose, they contribute nutrients to the soil, aiding in plant growth and maintenance and enhancing soil fertility. However, they break down slowly, so chopping or drying them and then grinding them into a powder will help speed up the process.
5. Nutshells
Nutshells have many practical uses in gardening, enhancing the appearance and functionality of garden spaces. When used as a natural mulch, nut shells help retain soil moisture and regulate temperature, creating a stable environment for plant growth. While any nutshell will work, be cautious when using walnut shells due to the presence of juglone. This compound can inhibit the growth of certain plants.
Apart from mulching, nut shells can also be used as a physical barrier to deter pests and improve drainage in potted plants, preventing waterlogging and promoting healthier root growth. The rough texture of the shells not only discourages slugs and snails but also adds an aesthetic touch to garden beds and containers.
6. Cooking water
The water used for boiling eggs or vegetables is not just waste, it’s a potential nutrient-rich resource for your plants. Packed with valuable minerals like calcium, this water can be repurposed to nourish your indoor or outdoor plants. After cooking, cool the water and store it in milk jugs or a watering can, then water as usual.
Using kitchen scraps for gardening is a sustainable and efficient method to enhance soil fertility and promote healthier plant growth while simultaneously addressing the issue of food waste. By repurposing common kitchen leftovers like eggshells, coffee grounds, banana peels, orange peels, and even used cooking water, gardeners can provide essential nutrients to their plants that foster robust growth and vitality.
