Plant most bulbs about two to three times as deep as the bulb is tall, measured from the soil surface to the top of the bulb. For many common spring bulbs, this usually means roughly 4–8 inches deep, depending on bulb size and soil type.

Basic depth rule

  • Plant bulbs at a depth of about 3× their height (a 2‑inch-tall bulb goes ~6 inches deep).
  • Measure depth from the finished soil surface down to the shoulder/top of the bulb, not the bottom of the hole.
  • In sandy soil, bulbs can go a bit deeper; in heavy clay, plant slightly shallower to avoid waterlogging.

Typical depths by bulb size

  • Large bulbs (tulips, daffodils, hyacinths): tops about 5–6 inches below soil surface (often a 6–8 inch planting hole).
  • Medium bulbs (grape hyacinths, some small alliums): tops around 3–4 inches deep.
  • Small bulbs (snowdrops, crocus, scilla, chionodoxa): tops about 2–3 inches deep.

Quick checks before planting

  • Ensure the pointy or sprouting end is facing up.
  • Do not count mulch in the planting depth; measure only the soil covering the bulb.
  • Make sure the soil drains well; sitting in waterlogged soil can rot bulbs even if the depth is correct.

Information gathered from public forums or data available on the internet and portrayed here.