Boxwood Hedge Spacing and Fertilizer: It Depends on the Variety

You're planting 18-inch boxwoods for a hedge and want spacing and fertilizer advice. The answer depends on three things the question didn't specify:

Critical Questions

1. Species/cultivar? Buxus sempervirens (American), B. microphylla (Littleleaf), 'Green Velvet', 'Winter Gem', 'Dee Runk'—each grows differently.
2. Current size/root ball? 18″ tall in a 1-gal pot vs. 18″ field-dug B&B changes spacing.
3. How fast do you want a solid hedge? Instant privacy vs. 3-year fill-in changes spacing dramatically.

General Guidelines (Once You Know the Above)

• Dwarf/slow growers (e.g., 'Green Velvet'): 12–18″ on center.
• Moderate (e.g., 'Winter Gem'): 18–24″ on center.
• Fast/upright (e.g., 'Dee Runk'): 24–30″ on center.
• Fertilizer: Balanced slow-release (10-10-10 or 14-14-14) in early spring. Avoid high nitrogen late season. Top-dress with compost annually.

Reply with the cultivar, container size, and timeline—I'll give you exact spacing and a fertilizing calendar.