Seed Planter Purpose
Gardeners, farmers and others who grow plants try to space their seeds as efficiently as possible. If the seeds are planted too closely together, the plants will compete for water and nutrients and will not grow strong and healthy. If the seeds are too far apart, however, the grower will not get the optimum yield. In order to germinate at the same time, seeds also need to be planted at a uniform depth. Seed planters accomplish both spacing and depth depth, and most can be adjusted for different size seeds.
Types of Seed Planters
Planters come in several varieties, including seed drills, plate planters and precision planters, as well as many different types optimized for different crops. Planters either dig furrows or poke individual holes in the ground as they are moved along, then drop seeds into the furrows or holes. Some use air streams to create a controlled flow of seeds into the furrows they dig. Others used grooved plates to pick up one seed at a time and drop it into a tube, which feeds it into a hole. Many seeders also incorporate harrows in the back, which rake earth over the freshly planted seeds as the planter passes, covering the seeds.
For planting large garden plots or fields, heavier equipment may be needed. Seed broadcasters are large funnels with rotary plates on the bottom that fling seeds across the desired area; broadcasters are best for grasses or cover crops. For tidier rows, wide grain drills are used; they have a number of "shoes" that drop from the seed box and deposit seeds (and fertilizer, if so equipped) into rows in the soil as the drill is pulled along.
Poor Man's Planter
Many seed planter mechanisms have been designed to let the small gardener plant seeds without stooping down and individually planting each hole. One such device is the poor man's planter. This homemade seed planter is nothing but a PVC pipe with an improvised funnel made from a pop bottle stuck in the top. To seed a particular spot, the gardener puts the end of the PVC pipe on that spot and drops a seed or two down the funnel.