Seed
Seeds are the ultimate tool to growing trees in Growtopia. They represent each and every spliceable item (except clothing). Each seed has a different appearance according to what the tree will grow to be when spliced that can easily differ the seed of Potted Daisy from that of Gem Sign. All items in Growtopia have their own seed form (even a Signal Jammer Seed exists). However, some of these seeds cannot be obtained in-game.
Using Seeds
To use seeds, simply tap a blank space above any block. Seeds can not be planted on blank above blank areas. If you want a item of that specific seed then simply plant and let the tree grow. If you know a specific recipe then add the appropiate seed.
Splicing
The process of combining two seeds is known as splicing. When you have a tree that was made from splicing two seeds and you attempt to add another seed, the dialogue, "It would be too dangerous to try to mix three seeds." appears. Some items in the game are unsplicable, meaning you cannot obtain them by splicing seeds and you will have to get the items through other means, such as purchases.