For urban gardeners, the question of whether to fertilize plants in planter boxes is common. The simple answer is: yes, it is generally necessary. Unlike plants in the ground, which can extend roots to search for nutrients, container plants are confined. Their roots exhaust the limited soil's nutrients quickly, and frequent watering leaches away essential elements.
Without supplemental feeding, plants may show stunted growth, pale or yellowing leaves, and poor flowering or fruiting. Fertilizer acts as a vital supplement, replenishing nitrogen, phosphorus, potassium, and micronutrients. The key is to fertilize wisely. Use a balanced, water-soluble, or slow-release fertilizer formulated for container plants. Always follow label instructions to avoid over-fertilization, which can harm roots. During the active growing season (spring and summer), feed your plants regularly. Reduce or stop feeding in fall and winter when growth slows. For edible plants like herbs and vegetables, consistent feeding is especially crucial for a good harvest. Therefore, while not every watering requires fertilizer, a consistent feeding schedule is a non-negotiable part of successful urban container gardening.