Security seems a weird thing to think about when you are growing crops but if you think about it as food prices rise, food supplies become more scarce, more difficult to grow due to erratic climatic conditions, large countries such as China and Russia buying up large tracts of fertile land for food growing and you can soon begin to see that you may need to turn your attention to security of your crops even in your own back garden let alone an allotment that you may have. With this in mind you might want to think about growing a perimeter hedge that consists of prickly plants such as the list below.

Hawthorne

This dense hedge grows 20 to 25 feet high and produces fragrant pink and white flowers. But beware the sharp thorns, which can range from 1 to 5 inches in length. Of course you do not have to have a hedge as tall as this as all the thorns are at the top of the tree. but this is a good deterrent and cheap to buy in bulk.

Hardy Orange

A fruit-bearing tree often used around prisons, hardy orange grows 15 to 20 feet high and wide and is covered to the ground with lacerating thorns. This is a plant that may not grow well in some parts of the UK but worth a try in a pot rather than in a hedge and then it dies and you are left with a hole in the hedge.

Black Locust

Resistant to rot and pollution, black locust produces creamy white flowers and a pair of short thorns at the base of each leaf. These thorns, although small are vicious and never fail to draw blood.

Pyrocantha

Pyracantha Firethorn 'Orange Glow' - Flowers white in June, with bright orange-red berries. Thorny stem. Height 10-15ft. Suitable for north or east-facing wall or as impenetrable hedging. This thorny evergreen shrub is one of the genus that produces red, yellow or orange berries in the Autumn can grow in any soil in the UK. This is a good shrub / plant that you can also "layer" if it gets too big.

Barberry

Also referred to as "sticker bushes, " these shrubs are characterized by their distinctive three-spined thorns.

Roses

Some varieties of this garden favourite will grow into a dense thicket that is impenetrable to trespassers. There are many types of "roses" available such as shrub, rambler and climber to mention just three. Ramblers and climbers are very similar but one has flowers once a year and the other continues to flower throughout the year. These ramblers and climbers are ideal to plant so they intertwine the rest of the shrubs.

Rosa 'Frau Dagmar Hastrup' is an excellent ground cover, pale pink flowers, very thorny stem. May to September. Plant with garden compost and bone-meal and another ground cover plant to interweave through other plants.

Creeping Juniper

Juniperis horizontalis 'Wiltonii' - Also known as 'Blue Rug' because it has long branches and its prostrate shape forms a flattened blue carpet. It has a thorny stem and foliage. This is a good one to plant at the base of any thorny hedge because as the shrubs grow they can tend to leave a gap at the bottom of the bushes. This is one reason why you cut new bushes as soon as you have planted them.

Juniperus x media 'Old Gold' - Evergreen. Golden-tipped foliage. Prickly foliage. Height 2ft. Spread 6ft. Low growing. Excellent ground cover. If you plant in a double staggered row then this one is ideal for planting in between the 2 rows to form a really impenetrable hedge.

Blue Spruce

Picea pungens 'Globosa' - Rigid branches, irregular dense blue, spiky needles. Height 1-1.25m x 75cm - 1 m. This is a slow growing shrub and it needs moist rich soil but is worth the effort for the blue flowers.

Common Holly

Ilex agulfolium - Large evergreen shrub, dark green spiked leaves. Large red berries on female plants only. Any well drained soil. Plant with garden compost and bone-meal. You will only get the berries if you plant a second Holly in the hedge or there is another holly within 250 m of yours. I hazard a guess that you can get self fertile hollies but it's worth having a few hollies in your hedge just for the berries for the birds.

Giant Rhubarb

(Gunnera manicata)- Giant rhubarb-like leaves on erect stems, abrasive foliage. Can grow up to 2.5m high. Plant by water-side for effect. Vicious plant and can take a long time to grow but if you have water nearby or a boggy area in your perimeter area then this is a good shrub for you.

Golden Bamboo

Phyllostachys aurea- Very graceful, forming thick clumps of up to 3.5m high. Less invasive than other bamboos. Hardy. Young shoots in spring. Although this has no thorns or spikes it grows so dense that after a few years even birds fly around it rather than through it.

Chinese Jujube

Zizyphus sativa - Medium sized tree with very spiny pendulous branches. Leaves glossy bright green. Bears clusters of small yellow flowers. Hardy in some parts of the UK although it has to be imported from China so there may be complications there. It's a nice enough plant but there are equally thorny plants easier to find.

Pencil Christmas Tree

Picea abias 'Cupressina' - Medium-sized tree of columnar habit, with ascending spiky branches. Attractive form with dense growth. Avoid dry chalky soils. This is also known as the monkey puzzle tree as it's the only tree in the world that NO monkey can climb.

Purple Berberis

Berberis thunbergil 'Atropurpurea'- Rich purple foliage. Thorny stem. Medium-sized deciduous. Any soil sunny position. There are at least 5 types of purple berberis and each type have different lengths of thorny spikes ranging from 12mm up to 70mm

Mountain Pine

Pinus mugo 'Mughus'- A very hardy, large shrub or small tree, with long sharp needles, of dense, bushy habit. Leaves in pairs, 3 - 4cm long, rigid and curved, dark green, cone.

Blue Pine

Picea pungens 'Hoopsii'- Small to medium-sized tree, spiky needled stem, densely conical habit, with vividly glaucous blue leaves. Likes moist, rich soil. This can also be layered.

Oleaster

Elaeagnus angustifolia - Small deciduous tree, about 4.5 to 6 m (15 to 20 feet) high. Smooth, dark brown branches that often bear spines and narrow, light green leaves that are silvery on the undersides. The flowers are small, greenish, fragrant, and silvery-scaled on the outside, as are the edible, olive-shaped, yellowish fruits, which are sweet but mealy. Hardy, wind resistant, tolerant of poor, dry sites, and thus useful in windbreak hedges.

Blackthorn

Prunus spinosa - Also called Sloe; spiny shrub. Usually grows less than 3.6 metres (12 feet) tall and has numerous, small leaves. Its dense growth makes it suitable for hedges. White flowers. Bluish-black fruit is used to flavour sloe gin.

Fuschia-flowered Gooseberry

Ribes speciosum - Fruit bush, spiny, produces greenish to greenish-pink flowers in clusters of two or three. Extremely hardy, thrive in moist, heavy clay soil in cool, humid climate so not always a one for the UK but worth a punt for the flowers.

Prickly ash (Zanthoxylum)

Although they will take some time to grow, the end result justifies the effort. They should deter even the most determined burglar and also thief of your food.

Hedges and shrubs in the front garden should be kept to a height of no more than 3 feet in order to avoid giving a burglar a screen behind which he can conceal himself.

Sea buckthorn

Sea-buckthorn is also a popular garden and landscaping shrub, particularly making a good vandal-proof barrier hedge with an aggressive basal shoot system exploited in some parts of the world as wind breaks and to stabilize riverbanks and steep slopes. They have value in northern climates for their landscape qualities, as the colourful berry clusters are retained through winter .Branches may be used by florists for designing ornaments.

Rubus (bramble),

Rubus is a genus of plant in the Family Rosaceae, Subfamily Rosoideae. These plants have prickles like roses and are often called brambles; this name is most often used for the blackberry and similar fruits that are also of rambling habit, and not used for those like the raspberry that grow as upright canes. Their fruit, called bramble fruit, is a wonderful crop that give a product from you hedge and with age these provide absolutely vicious spikes all along the stem. To continue to get fruit you need to cut out the branches that have fruited THIS YEAR. Although these are then no good to grow on as a viable crop producing fruit  there is no reason that you have to remove these from your hedge and thus as they die back to a golden brown colour they still have their spikes to protect you. If you don't want the fruit then just leave it to ramble like rosa rugosa and let the mice and birds have the fruit.

In addition, the following thorny plants can also be considered:

Aralia,

Chaenomeles,

Colletia,

Crataegus (including hawthorn/may),

Maclura,

Mahonia,

Oplopanax,

Osmanthus,

Poncirus,

Rhamnus,

Smilax.

I hope to update these plants with more time.

Planting

The most environmentally beneficial hedge to plant in a home garden area will be one comprised of a range of locally native species of local provenance. The stock proof, vandal proof, thief proof nature of such a mixed species hedgerow need not be compromised, as long as at least 75% of the species mix is composed of thorny species, i.e. Hawthorn (Crataegus monogyna) and Blackthorn (Prunus spinosa).

Planting should be carried out between November and March. Autumn planting is preferable as it usually results in better establishment although there is an increased danger of damage by rabbits and hares during the winter months. No planting should be done in very wet, frosty or snowy conditions. It is possible to plant shrubs at any time of the year and you can get pot grown species all year round but why pay something like £6 -£10 per plant when you can buy bare rooted bushes at around 10p each in the autumn.

Establishment of new plants in an old hedge is often difficult as the site is usually dry and leached of nutrients. It is essential to ‘improve’ the soil in such circumstances by digging in well-rotted farmyard manure. This is not easy as many roots runs into each other and although there is a gap in the top growth there isn't in the soil.

When gapping-up an existing hedgerow adjacent plants can be trimmed back or coppiced, promoting more successful establishment of new plants due to increased light levels. Alternatively shade tolerant species, such as Blackthorn or Holly, could be planted next to established shrubs.

The normal method is to plant new hedges without constructing a bank but when replanting an old hedge line the planting should follow the top of the bank, if present. The species of trees and shrubs planted should match those in surviving sections of the hedge or in adjoining hedges where possible so that areas do not stand out as being new and possibly easier to pull out.
Planting can be carried out in two main ways:

(i) Cultivated strip planting
In a cultivated strip, approximately 60cm wide by 25cm deep. This ensures that the roots of each plant are placed into the optimum cultivated conditions for good root development. You dig over a strip of land to the dimensions mentioned and add in lots of manure, blood fish and bone meal, calcified seaweed and mix in all together.

(ii) Slit planting
By cutting a slit in the ground and holding it open with a spade whilst the roots of the plant are carefully inserted and spread downwards.
The plants should be set in at the same depth as they were in the nursery[you can tell the depth by looking at the ring mark on the stem] and the soil must be firmed well in around the roots.

A double staggered row of plants produces a dense, solid hedge with suitable stems for laying. This method uses 7 plants per metre, in two rows about 30cm apart with plants at approximately 45cm between each row.

For example

.   30   .   30   .    30  .

    .   30   .   30    .

Wide hedgerows may be established where space is available and have the benefit of creating wider landscape and conservation corridors. The normal method would be to plant a double row hedge as above, with a distance between the rows of 1-1.5m, and to plant a varied row of trees between these rows. Damaged or dead shoots should be removed at planting.

If you plant bare rooted plants of about 30cm to 60 cm then when they are planted during the dormant season of November to March you should then cut them down to about 20 cm tall. My first hedge was planted without cutting them back as I thought it was a waste of money but since then the base of the hedge became bare and was easy to climb under. This has been rectified by layering the hedge but cutting the bare rooted plants down at planting time is the better option and will encourage the cuttings to bush out and keep more spines lower down. Of course you can always plant these cuttings in a pot of compost, cover with a bag and put in the cold frame to see if they take root.