Harvesting
Harvesting is the act of collecting items, generally from plants or trees.
How to Harvest
Harvesting Plants
To harvest from plants, a blockhead must use a hand, machete, or spade to destroy some or all of a plant once the plant has grown to be two blocks tall. Using a tool is the most effective way to harvest seeds or foods from plants. Additionally, a tin spade won't wear from harvesting plants.
The second way to harvest from plants is to wait until the plant is full grown for a while, and then the top portion of the plant will automatically "die" and fall off. When this happens, one seed or food item will fall, and it can be collected. However, it takes quite a bit longer to collect a large amount of items.
Harvesting Trees
Harvesting from trees is done a little bit differently. Trees grow from small to large, and so they start off as small blocks of leaves. After a while, they'll grow and then grow some more, and eventually they will reach "maturity" (typically when a trunk can be seen below the leaves) and will start producing fruit or seeds. When trees produce fruit or seeds, the items - the food for the type of tree you planted - will spawn hanging off of the branches of the tree every once in a while. A blockhead must pick up these items themselves, as they will not drop nor will they stay on indefinitely, as after a while the items will despawn and disappear.
As the tree continues to grow, it will grow more branches and grow taller. The branches can be harvested using a machete to give a blockhead three sticks. The middle of the tree, where the branches don't have air showing between the and show wood instead (the tree's trunk), is where it can be destroyed using an axe to collect wood. It is best to keep your trees small (but not too small) since they will both grow faster, and live longer as long as you do so.