However, do not remove the bulb tops until they are dead. Bulb planting chart. Lilies normally are planted in the spring, while autumn crocuses normally are planted in midsummer. All other bulbs shown are planted in the fall. Planting depths are for well-drained soils.
Bulbs do best in a sandy, clay loam.
In heavier soils, they should be planted 1 to 2 inches higher. For fertilizer to be effective, it must be present in the vicinity of the roots. Excavate the bed to the bulbs' planting depth. Apply the fertilizer and soil amendments at this level, and spade or rototill the soil to a depth of 3 or 4 inches. Aeration is the most important aspect of soil preparation.