Mid-season fertilization

Plant health varies throughout the campus terrace garden. Some of this variability seems to correspond with different compost applications.

Plants are generally healthy in the section of the garden that received compost during the first week of March. These include potatoes, peas, beans, kale, and pac choi.

The section that received compost in the first week of April is less healthy. It was seeded to carrots, parsnips, and beets. Germination was poor, so some of this section had to be re-seeded. Growth has been slow throughout. We see bright red beet leaves, suggesting phosphorus deficiency. Even the purslane grows much more slowly here than in other areas of the garden.

The final compost application was made in late May. This area was planted to tomato, pepper, basil, squash, cucumber, beans, corn, and sunflower. Most of these crops look OK, but there are some signs of nitrogen deficiency.

We decided to side-dress with organic fertilizer. We blended 25 pounds of bone meal (2-14-0), 50 pounds of alfalfa meal (3-0-2), and 50 pounds of kelp meal (1-0.15-2). This amounted to 125 pounds of fertilizer with a 2-2.9-1.6 analysis.

On June 16th the students side-dressed plants in the green shaded areas on the map below with the dry fertilizer blend. These same areas were also fertilized with 1.5 liters of fish fertilizer (2.75-1-2). The total fertilized areas was 171 square meters, or 0.042 acres. The additional fertilizer should eventually add about 62 pounds of nitrogen per acre, 86 pounds of phosphorus per acre, and 50 pounds of potassium per acre.