The spacing of your hedging plants will depend on a few key factors. One of the most important factors is how quickly you want your hedge to form. The further apart you space your plants, the longer it will take for them to grow together and form a solid hedge. However, planting too close together can also have its drawbacks. Overcrowding can cause the plants to compete for resources, leading to stunted growth and an unhealthy hedge.
Another important factor is the size of the plants you have bought. If you're planting young plants, you may need to space them closer together to achieve a good initial planting density. However, if you're starting with larger, bushier plants, you may be able to space them further apart and still achieve a solid hedge.
Another consideration is the ultimate height of your hedge. If you're planting a tall hedge, you'll need to give the plants enough room to grow. This may mean spacing them further apart than you would for a shorter hedge.