Hedge plants are used more in the United Kingdom as definers of territory and ownership than all other types of boundary marker put together. Hedging is ideal for delineating land rights as they define - when established - where one person's ownership begins and ends. They are usually preferable to walls, railings and fencing. They are extremely permanent and apart from the odd clip they are self maintaining (a fence has done well if it lasts 20 years - a hedge is disappointed if it does not reach 150). You can plant a hedge faster than you can build a wall and for far less money...
Most often, hedge plants are used to define or clarify internal or external boundaries in gardens, parks, farms and estates and they provide good habitat while doing so. When they are grown as internal dividers, hedges can be used to edge paths and drives, define formal plantings and rose beds and to separate growing areas in vegetable gardens as well as split up fields.
However external hedging often has a 'defensive' purpose as well. Property crime is at an all time high. Supposedly private gardens are abused as havens for muggers and addicts and as convenient dumping grounds for fly tippers. One of the fastest growing areas of theft is stealing fruit and vegetables from allotment plots.
Because they need defensive qualities barrier hedge plants should be well armed. For the budget conscious, hawthorn and blackthorn work extremely well. Barberry is a good looking plant - Berberis thunbergii Atropurpurea carries deep purple foliage while Berberis julianae colours fantastically in the autumn and both have needle sharp spines.
The Ramanas Rose (Rosa rugosa) which flowers early and continuously in shades of carmine and white, and which carries large rosehips, sometimes well into the new year, is tough enough to be cut with shears or a powered trimmer. It also has the great merits of growing almost anywhere except in the shade and of being extremely prickly. All the above are good subjects to be planted bare-rooted in the winter months. Remember that you can save a lot of money buying bare-root hedge plants as they more economic than container grown stock.
At the top end of the market Holly (Ilex aquifolium) works as does Pyracantha. Both need to be bought in containers as they do not establish well when planted bare-rooted (which of course is the reason they are dearer). They are also a little more formal than the bare-root plants above as they trim well and hold their foliage through the winter. Holly flowers are unshowy although sweetly scented nut glossy leaves - sometimes variegated berries before Christmas compensate. Pyracantha is definitely more eye-catching as it is covered with racemes of white flowers in early summer and is laden with red, gold or orange berries, depending on variety, in autumn. .
Although hedges cannot solve every problem, they are wonderfully efficient barriers. Try to get through a holly hedge and see what happens....
To make a good barrier hedge all of the above (with the exception of Pyracantha and holly) are best planted in a double row leaving a gap of about 30 cms between rows. You need three plants per the metre in a row and the plants should be staggered between the rows so that if you joined them up you would make a zigzag. Pyracantha (sometimes known as Firethorn) - is so well armed that even a goat would think twice about having a nibble. One row is plenty, but still planted at three plants per metre.
To make the hedge densely branched which it needs to be to be an effective barrier, you should cut all the bare root stock back by 50% on the day they are planted. Container grown plants should have their height reduced by 30%. The idea is the same in both cases - trimming plants back makes them grow side branches that fill out the hedge and make it impenetrable.
In a surprisingly short time, your hedge will be impassable, and something that is an effective barrier to cattle and horses, will most certainly deter your typical yob, bully or thief.
Anna Stenning is an expert on hedge plants having recently planted a new hedging as opposed to building a new wall.