Bulbs are what you place in order to grown various flowers and trees. They are an important part of earning the Horticulturalist Achievement.

For more information on specific bulbs and their flowers/trees, see the individual pages:

How to Obtain

You can get bulbs by looting them from chests or by trading for them in market worlds. Occasionally, when mining a fully-grown plant using a spade, you can recoup a bulb in addition to the flower/tree.

How to Use

Bulbs must always be placed on some sort of backdrop, be that earth backdrop or backdrop that you place. In all cases, there must be clear sky above the bulb.

Ghost tree bulbs will only grow in hell biomes, and cactus flower bulbs will only grow in desert biomes. All other bulbs will only grow in purified temperate biomes.

The better quality your spade is, and the higher your horticulture skill level, the greater your chances of recouping a bulb from a plant when you mine it with a spade.

All bulb-grown plants go through 3 stages of growth. Mining either of the two immature stages will cause flax to go into your inventory. You can tell if the plant is fully-grown because the bulb will transform into a block of compost.