Cilantro is a versatile herb that thrives in outdoor plant boxes, especially when paired with the right companion plants. To create a flourishing cilantro garden, consider planting basil, dill, or parsley nearby, as they share similar sunlight and watering needs. Leafy greens like spinach and lettuce also make excellent companions, as they provide shade to cilantro roots, preventing premature bolting. Avoid planting fennel or overly aggressive herbs like mint, which can compete for nutrients. For optimal growth, ensure your plant box has well-draining soil and receives at least 6 hours of sunlight daily. Rotate cilantro with other herbs or vegetables to maintain soil health and reduce pest issues. With the right plant combinations, your outdoor cilantro garden will yield fresh, aromatic leaves all season long.