Spread a 3-inch layer of mulch over the daffodil bed after planting the bulbs in fall. The mulch prevents cool-season weeds from overtaking the bed while the bulbs are still dormant. Bark and pine straw provide a suitable mulch that suppresses most weed plants.
Replenish the mulch layer to maintain the 3-inch depth in spring when the first daffodil leaves begin to emerge. The thick mulch layer doesn't prevent daffodil growth but suppresses many spring weeds.
Inspect the daffodil bed weekly for weeds. Grasp the weeds near the soil surface and pull them straight up before they become deeply rooted. Avoid digging out weeds, as this can damage nearby daffodil bulbs.
Cut back the daffodil foliage once it yellows and falls over, 4 to 6 weeks after bloom. The dead foliage makes it difficult to see new weed growth in the bed.
Plant annual flowers or summer-perennials in the bed once the daffodils die back. The flowers grow and bloom during the summer months and provide a living mulch that helps prevent weed growth while the bulbs are dormant.