URBAN PLANTER BOXES

The realistic number depends less on how many seedlings you can squeeze in and more on soil volume, airflow, and mature plant size. As a rule, give each pepper plant about 5–10 gallons (19–38 L) of potting mix and 12–18 inches (30–45 cm) of spacing. Compact or dwarf varieties can fit closer, while full-size bell and hot peppers need more room. For a common urban planter box that is 12 inches deep, use these estimates: 24 x 12 inches: 1–2 compact plants; 36 x 12 inches: 2–3 compact plants or 2 standard plants; 48 x 12 inches: 3–4 compact plants or 2–3 standard plants; 60 x 18 inches: 4–6 compact plants or 3–4 standard plants. If the box is less than 10–12 inches deep, stick to one row of dwarf peppers or grow herbs and lettuce instead. Peppers also need at least 6–8 hours of direct sun, drainage holes, and good airflow to reduce disease. Don’t overcrowd: tight spacing may look full early in the season, but plants will compete for water and nutrients, shade each other, and produce fewer peppers. Use a quality potting mix, mulch lightly, support tall varieties with a stake, and prune only as needed. For the best harvest, choose compact varieties for shallow boxes and give standard peppers the larger end of the spacing range.