Bulb Planting Depth Chart (and How to Store Bulbs Before Planting)

Two questions decide whether a bag of bulbs becomes flowers: how deep you plant them, and what you do with them if you cannot plant them today. This is the reference page we send customers who ask both.

Planting depth and spacing chart

Measure depth from the base of the bulb to the soil surface, not from the tip. The general rule is three times the bulb’s height; the chart below shows what that means in practice.

Storing bulbs before planting

Bulbs are alive and respiring. The four enemies are heat, moisture, light and ethylene gas.

• Temperature: 50–60°F (10–15°C) is the safe range for most dormant bulbs. A cool garage, cellar or unheated room works.
• Ventilation: a paper bag, cardboard box or mesh tray with holes. Never a sealed plastic bag — condensation is what causes mould.
• Darkness: light triggers premature sprouting.
• Ethylene: keep bulbs away from ripening fruit, especially apples and bananas, which release gas that aborts the flower inside the bulb.
• Rodents: check boxes monthly and store tulips and crocus where mice cannot reach them.

How long can bulbs wait?

Tulips, daffodils and hyacinths hold for four to six weeks in good conditions. Crocus and snowdrops are less forgiving — plant within two to three weeks. Bare-root perennials and peonies should go in the ground within a week of arrival; if you must delay, heel them into damp compost rather than leaving them in the packaging.

Signs a bulb is still good

Firm, heavy and dry-skinned: plant it. A little blue-green mould on the papery tunic: wipe it off and plant. Soft, sour-smelling, or collapsing under light pressure: discard it — it will not grow and may spread rot to healthy bulbs in the same bag. A bulb with a small green shoot is still viable; plant it promptly and it will simply emerge early.

What to do if the ground is frozen

Pot the bulbs in free-draining compost, water once, and keep the pots somewhere cold but frost-free — an unheated porch, a cold frame, or against a sheltered wall. Move them into light when shoots appear, and plant out the whole rootball in early spring. Tulips planted this way often flower only a week or two later than those planted in October.

Every order from our catalogue ships with planting notes, and the FAQ covers guarantees, depth questions and what to do about mould. If you are still unsure, email plantbulbshop@gmail.com with your zone and soil type.