Which plant makes a good hedge?
If your thing is a formal hedge, yes, a single species hedge looks good. Hornbeam, beech, hawthorn for security, or if you have time, yew are the best native species. We prefer a mixed hedge; more interesting and better for wildlife.
When should you plant a hedge?
Winter. Although you can get potted plants, bare root is the way to go, which means planting between November - end March. Much cheaper and better establishment. If money is no object you can also buy "instant hedging", which you can plant all year round but which will need irrigating.
What hedge grows in shade?
Many native species grow in light shade - most, I'd say. For deeper shade use holly, yew, hawthorn, spindle, hazel, wild privet.
What are the best hedges for privacy?
Tall thick hedges. No, honestly, any native species will give you a good privacy hedge so long as it's managed properly. You can't see anything through a 1m wide mixed hedge, even in winter.
What are the best hedges for security?
Do hedge plants need guards?
Generally, yes. It's a damn nuisance. The plastic spirals don't biodegrade and stunt development of the plants if not removed promptly. The exceptions are when there are no herbivores about - so urban situations or where there's good fencing. The hunt is on for a biodegradable guard.