Bramble

Bramble in Manchester, England. Note the unripe fruit on second-year side shoots in the background and late flowers (13 August 20017) from the tip-flowering of first-year growth.

Pink blackberry flower, Wellington, New Zealand

In British English, a "bramble" is any rough (usually wild) tangled prickly shrub—specifically the blackberry bush (Rubus fruticosus)—or any hybrid of similar appearance, with thorny stems. Bramble or brambleberry may also refer to the blackberry fruit or products of its fruit (e.g., bramble jelly).^[1] The shrub grows abundantly in all parts of the British Isles and harvesting the fruits in late summer and autumn is often considered a favourite pastime. It can also become a nuisance in gardens, sending down its strong suckering roots amongst hedges and shrubs. Many consider it a weed due its tendency to grow in neglected areas and its sharp, tough thorns which can be hazardous to children and pets.^[2]

Elsewhere, such as in the United States, the term "bramble" also refers to other members of the Rubus genus, which may or may not have prickly stems—notably the raspberry (Rubus idaeus) or its hybrids.

Etymology

"Bramble" comes from Germanic bram-bezi, whence come also German Brombeere, Dutch Braambes and French framboise. It originated before the year 1000; Middle English; Old English bræmbel, variant of brǣmel, equivalent to brǣm- (cognate with Dutch braam broom ).^[3]

Description

Bramble bushes have long, thorny, arching shoots and root easily.^[4] They send up long, arching canes that do not flower or set fruit until the second year of growth. Brambles usually have trifoliate or palmately-compound leaves.

Bramble fruits are aggregate fruits.^[5] Each small unit is called a drupelet. In some, such as the blackberry, the flower receptacle is elongated and part of the ripe fruit, making the blackberry an aggregate-accessory fruit.

Uses

The blackberry is a bramble

Many species are grown and bred for their fruit. Ornamental species can be grown for flowers (e.g. Rubus trilobus), for their ornamental stems (e.g. Rubus cockburnianus) and some as ground cover (e.g. Rubus tricolor). Members of the Rubus genus tend to have a brittle, porous core and an oily residue along the stalk which makes them ideal to burn, even in damp climates. The thorny varieties are sometimes grown for game cover and occasionally for protection.

Most species are important for their conservation and wildlife value in their native range. The flowers attract nectar-feeding butterflies and hoverflies, and are a particular favourite of Volucella pellucens.

Brambles are important food plants for the larvae of several species of Lepidoptera—see list of Lepidoptera that feed on Rubus. The leaves of brambles are often used as a main food source for captive stick insects. Many birds, such as the common blackbird, and some mammals will feed on the nutritious fruits in autumn.

Split bramble stems are traditionally used as binding material for straw in production of lip-work basketry, such as lip-work chairs and bee skeps and sometimes used to protect other fruits such as strawberries.

Bramble leaves can be used to feed most Phasmatodea. Young leaves contain a toxin that can be harmful to many species of Phasmatodea, however this only occurs up until their third instar, by which time they have developed an immunity to it.

Control

Scything woodland brambles in Kent, England, preparatory to poisoning emerging new spring shoots

Brambles are difficult to eradicate once they have become established. Early action by hand pulling with a gloved hand and digging young seedlings as soon as they are seen will save a lot of hard work later. A thick mulch of chipped bark or compost will also make it much easier to pull out recently germinated seeds in the spring. Light but established infestations in friable, workable soils may be removed by cutting back the stems to about 1 foot (300 mm) above the ground, to leave a handle, and forking out the bramble stump with as much of the root as possible. Anything left below-ground may regenerate.

Heavy infestations may make the land completely impenetrable and will require cutting first just to access the stems. The root systems will also be so pervasive that removing them would require digging up the entire area; doing this in woodland areas will cause unacceptable damage to the surface roots of trees and to flowering bulbs and should be avoided. In this case, chemical control using a selective weedkiller such as triclopyr to wet the photosynthesising bramble leaves is very effective if applied in accordance with the manufacturer's instructions. However, a heavily infested area of uncut brambles will require an inordinate amount of poison to wet the leaves; it is far cheaper, and more effective, to cut the area as close to ground level as possible in the spring, clear the debris into piles to reveal the ground surface and to accurately spot spray^[6] the shoots that will emerge two to three weeks later as soon as they have a small amount of new foliage. This will kill the plant back into its root system using a small fraction of the poison required to spray whole bushes. The area may first be cleared using a tractor-mounted rotary mower, motorised string trimmer or with a scythe. A short-bladed, 24 inches (610 mm), scythe in good hands can be faster than using a string trimmer, leaves a neater cut close to the ground, avoids collateral damage to other plants that are desirable to keep, and deposits the cut debris aligned in swathes that are easier to remove and stack. The area must be cut and cleared at some point anyway and it is easier to clear the debris while green and flexible than dead and dry, so clearing when green then spraying a little is more efficient than spraying a lot then clearing when dry.^[7]

Triclopyr is highly selective, it only affects actively photosynthesising monocots, leaving grass, and flowering dicots such as narcissus and bluebell bulbs, undamaged. It also breaks down harmlessly in the soil within about six weeks leaving no toxic residuals.^[8] Glyphosate is also effective but must be used with much greater care and will damage other woodland plants.

Cultivation

There are many different systems developed for the commercial culture of blackberries and raspberries. Bramble cultivars are separated into several categories based on their growth habit. They are categorised as erect, semi-erect, or trailing.

References

Wikimedia Commons has media related to Rubus.