Introduction Most companion planting guides focus on the perfect pairings—tomatoes with basil, beans with corn, marigolds with just about everything. But here’s the truth: knowing what not to plant together is just as important as knowing the “good” combos. Over the years, I’ve seen plenty of gardens fail not because of pests or poor soil, but because of simple companion planting mistakes. These errors are easy to make, especially for beginners, and they can quietly sabotage your harvest. In this guide, we’ll uncover the bad companion plants and overlooked pitfalls that no one really talks about—plus the quick fixes that…