Absolutely, fertilizing is generally recommended for soil in urban planter boxes. Unlike plants in the ground, which can send roots far to seek nutrients, container plants are confined. Their roots exhaust the limited nutrients in the potting mix relatively quickly with each watering. Regular fertilization replenishes these essential elements, supporting robust growth, better flowering, and higher yields for edible plants.
For optimal results, begin with a high-quality potting mix that often contains a starter charge of fertilizer. Then, establish a feeding schedule. A balanced, water-soluble fertilizer applied every 1-2 weeks during the growing season is a common and effective method. Alternatively, you can incorporate a slow-release granular fertilizer into the soil at planting time, which feeds plants steadily for several months. Always follow the product's label instructions to avoid over-fertilization, which can harm plant roots and soil health.
Consider organic options like compost, worm castings, or fish emulsion to enrich the soil ecosystem naturally. Remember, the key is consistent, moderate feeding tailored to your specific plants' needs, ensuring your urban green space remains vibrant and productive throughout the season.