Organic seeds are seeds that come from plants grown without synthetic pesticides, herbicides, or genetically modified organisms (GMOs). Choosing organic seeds for growing tomatoes and onions ensures that you are starting with plants that have been cultivated in a way that promotes biodiversity and soil health. Organic seeds often produce stronger, healthier plants that are more resilient to pests and diseases. Additionally, using organic seeds supports sustainable farming practices and helps preserve heirloom varieties, which can contribute to a diverse ecosystem in your garden.