Here are 6 homemade fertilizers you can use for your plants: 1. *Coffee Ground Fertilizer* Mix 1/2 cup of used coffee grounds with 1 gallon of water. Let it steep for 24-48 hours. Strain and use as a liquid fertilizer. 2. *Banana Peel Fertilizer* Bury banana peels around the base of your plants or mix them into the soil. They're rich in potassium, magnesium, and sulfur. 3. *Eggshell Fertilizer* Crush eggshells and mix them into the soil. They provide calcium, which promotes healthy plant growth.