Keeping your urban planter boxes lush and productive requires proper nutrition. Unlike plants in the ground, container plants have limited access to soil nutrients, which are quickly depleted by watering. Fertilizing is therefore essential for their health and vitality.
First, choose the right fertilizer. A balanced, water-soluble fertilizer (with equal parts Nitrogen, Phosphorus, and Potassium, like a 10-10-10 formula) is a great all-purpose choice. For edible plants like herbs and vegetables, organic options such as fish emulsion or seaweed extract are excellent.
Timing is crucial. Begin fertilizing about 4-6 weeks after planting, as most potting mixes contain a small initial nutrient charge. During the active growing season (spring and summer), feed your plants every 1-2 weeks. Reduce or stop fertilizing in the fall and winter when plant growth naturally slows down.
The method is simple. Always water your plants thoroughly with plain water before applying fertilizer. This prevents root burn. Then, mix the fertilizer according to the package directions—never use more than recommended. Apply the solution evenly to the soil until it begins to drain from the bottom of the box.
For the best results, observe your plants. Yellowing leaves can indicate a need for nitrogen, while a lack of flowers might suggest a need for more phosphorus. Adjust your feeding schedule based on your plants' responses, and you'll enjoy a vibrant urban garden all season long.