Raspberry x Blackberry cross.
A Raspberry x Blackberry cross.

Brambles

Rubus spp

Origin:

Varieties are derived from Europe and North America. There are also native varieties in Australia and Asia.

Climate:

The most suitable brambles for the Perth area are boysenberries and youngberries. Raspberries and other Rubus species are more suitable for cooler climates such as the South West. There are also some blackberry varieties such a Murrindindi (thornless) and karaka berry which will grow and yield well in Perth.

Plant Description:

Brambles include blackberries and crosses with other Rubus species such as raspberries. The precise number of named species is unknown, but is somewhere between 400 and 750. There are 12 subgenera and many hybrids. The stems are usually thorny and may have trailing stems up to 7m long. There are some thornless cultivars.

Relatives:

Rosaceae Family, which includes stone fruit, pip fruit, loquats, and many others.

Soils:

Grow in well-drained soil. Mulch around the bushes. Good irrigation is needed, especially in summer.

Propagation:

Propagation is straightforward, so plants can easily be bulked up. Stems that touch the soil will root and can be removed for planting. Nursery plants are cheap.

Cultivars:

Brambles may include named blackberries, boysenberries, loganberries, keriberries, marion berries, silvan berries, tayberries and youngberries. Boysenberries and youngberries are raspberry/blackberry crosses, but the boysenberry has an additional loganberry parentage and the youngberry has an additional dewberry parentage. Youngberries are higher yielding. The fruit is shinier, lighter and more elongated, with less flavour than boysenberries. Fruit size is 30-35mm long by 15mm wide and is smaller than boysenberries (up to 35-40 cm long by 20-25cm wide)

Flowering and Pollination:

The flowers are borne in spring. Often white in colour, some are pink. Pollinated by insects, they readily set fruit.

Cultivation:

Plant in full sun at 0.6 to 1.0m apart next to a wall or fence. A wire trellis may be attached to the wall or fence to support the stems. Much pruning and training is needed from January to June. Shoots will grow rapidly and may grow downwards where they will root in the soil. They need to be trained twice weekly to fill bare spaces on the wall. New growth in spring and summer may trail along the ground. Use a complete NPK fertiliser every 2 months in the warmer months from September onwards. Mulch around the plants.

Wind Tolerance:

Good tolerance.

Pruning:

Weak growth should be removed. In February, the old canes (2 or 3 years old) should be removed. The trailing new growth should be picked up and the shoots should be fixed and trained to the wires on the wall or fence.

Suckers should be removed to prevent spread into surrounding garden beds. A plastic barrier 60cm deep can help minimise this problem.

The Fruit:

Technically, the fruits are not berries, but an aggregate of drupelets. Most ripen in late spring or summer. The soft, juicy, fruits are usually purple or black but can also range from white, through yellow to red. There are many edible seeds.

Fruit Production and Harvesting:

Boysenberries and youngberries will fruit on old wood from November to December in Perth. Youngberries commence cropping slightly before the boysenberries. A plant may yield 1.5 to 2kg per season. Fruit may need to be picked daily.

Fruit Uses:

Berries contain vitamin C, fibre, carbohydrates and potassium. They have a short shelf life. Store at 0 to 5°C in a refrigerator. Fruit can be eaten fresh, or frozen for later dessert use. They may also be used in ice creams, juices, jams, jellies and tarts.

Pests and Diseases:

There are few problems in the Perth area, but scale insects on the stems may need to be controlled. Black spots on the leaves may be controlled with mancozeb.

Comments:

Rubus are expensive in shops, as they are highly perishable and labour costs for fruit picking are high for commercial growers. They need much labour and good management. Blackberries in particular are notoriously weedy and invasive, and need to be controlled. Plants are thorny and suckers will be a problem unless controlled, but the gardener is rewarded with excellent fruit quality. They are also useful for covering walls and fences. Mulberries are of similar type, but brambles have the advantage of never needing ladders.