Planting Density Guide: How Many Bulbs Per Square Foot

Planting Density Guide: How Many Flower Bulbs Per Square Foot

Getting the right number of bulbs per square foot is essential for a successful bulb display. Too sparse, and the impact is lost. Too dense, and airflow and bloom spacing suffer. Use the following guidelines to plan both fall- and spring-planted bulbs.

Fall-Planted Bulbs (Spring-Blooming)

These are planted in autumn for spring color.

Large Bulbs (6–8" planting depth)
Examples: Tulips, Daffodils, Hyacinths, Alliums (large types like Allium giganteum)

• Display planting: 5–7 bulbs/sq ft
• Naturalized effect: 3–5 bulbs/sq ft
• Massed impact (e.g., for public plantings): 7–10 bulbs/sq ft (especially tulips)

Medium Bulbs (4–6" planting depth)
Examples: Narcissus Tazetta types, Anemone coronaria, Muscari, Scilla, small alliums

• Display planting: 10–12 bulbs/sq ft
• Naturalized: 8–10 bulbs/sq ft
• Massed or edging: 12–15 bulbs/sq ft

Small Bulbs (2–4" planting depth)
Examples: Crocus, Chionodoxa, Galanthus (Snowdrops), Iris reticulata

• Display planting: 12–15 bulbs/sq ft
• Naturalized: 10–12 bulbs/sq ft
• Carpet effect: 15–20 bulbs/sq ft

Spring-Planted Bulbs (Summer-Blooming)

These are tender bulbs planted in spring after frost danger has passed.

Large Bulbs/Corms (6–8"+ deep)
Examples: Lilies, Gladiolus, Canna, Crinum

• Specimen planting: 1–2 bulbs/sq ft
• Mixed borders: 2–3 bulbs/sq ft
• Massed display: 3–4 bulbs/sq ft (esp. Asiatic or Oriental lilies)

Medium Bulbs (4–6" depth)
Examples: Dahlias (tubers), Calla Lilies, Tuberous Begonias

• Display beds: 3–5 tubers or bulbs/sq ft
• Dense impact: 5–6/sq ft for low-growing types (e.g., dwarf dahlias, border begonias)

Small Bulbs (2–4" depth)
Examples: Freesia, Sparaxis, Ixias, Brodiaea

• Display planting: 10–12 bulbs/sq ft
• Massed color: 12–16 bulbs/sq ft

 Planning Tips

• Containers: Increase density by 25–50%, especially in seasonal pots where airflow and naturalizing aren't concerns.
• Bulb mixes: Layer different depths for succession planting (e.g., Muscari over tulips).
• Mechanized planting: Use maximum recommended rates for sweeping displays in parks and festivals.
• Wildlife pressure? Plant densely in fenced areas or use deterrents—sparse plantings make individual bulbs easier targets.