Planting out Blackberries
The best time to plant is late autumn, but any time from then until early spring is fine, provided theis not waterlogged or frozen. The distance between plants varies a great deal, according to the strength of the variety. Merton Early needs only about 1.2 m (4’) between plants, while Parsley-Leaved, Merton
Thornless, and John Innes need about 2.4 m (8’). The very vigorous growers, such as Bedford Giant and Himalaya Giant should really have plenty of room to spread out, say, 3.5-4.5 m (12-15’) between each plant. If you are uncertain about a particular variety, ask your nurseryman or garden centre for specific planting distances.
Whatever the variety, if you are planting more than one row, leave at least 1.8 m (6’) between them. This not only allows you to prune and harvest easily but permits sunlight to reach the plants, which is necessary for new growth to be hardened properly, and for the berries to become fully ripened.
Dig the planting hole 10-12.5 cm (4-5”) deep. Cut off broken roots and set the plants in with the roots spread out naturally to their full length. The crown should be level with the soil surface. Crumble the soil over the roots, firming it gently as you go, until the soil is level with that surrounding it. If the soil is dry, give the newly planted canes a thorough watering.
After planting, cut down the canes to 23 cm (9”). Although this precludes fruiting the first year, it will encourage the roots to settle in and produce healthy future growth. If you leave the canes uncut, the first year’s crop will be poor, and it will take several years for the plant to recover fully, if it does so at all, from the strain of premature fruiting.
Blackberries need exposure to as much light and air as possible, and the various systems of training are all based on this. Basically, the current year’s shoots are kept tied in and separate from the older fruiting shoots; the young shoots are trained upright with the fruiting canes radiating out on either side of them. When the fruiting canes have finished cropping, they are cut away completely, and the young canes are retied to take their place. The centre is then left empty, and ready to be filled by the following year’s new canes. This may sound a bit overwhelming, but it is not at all difficult.
Do not be tempted to allow your blackberries to grow unpruned and untrained. Overgrown blackberry thickets usually have only dead or diseased wood in the centre, with the healthy fruiting canes on the outside, where light and air are available. Growing blackberries in this way is a waste of space that very few gardens nowadays can afford. During the first summer after planting, usually only one or two canes will grow, and these will not fruit. Wearing stout gloves as protection against thorns, gradually tie them up and along the top, or nearest suitable wire. Late the following winter, check the canes for die-back or frost damage, and remove any dead wood. If the canes have grown too vigorously for the space allotted them, cut them back by about 60-90 cm (2-3’), and any side-shoots to within a hand span of the main stem. Early next summer, begin training them along the wires provided.
Although there will only be a couple of fruiting canes the first season, from the second summer onwards there should be 8-10 canes per plant.
There are several patterns of training, but the simplest is to weave the fruiting canes between the bottom and third wire, leaving the centre empty for new canes. Choose the two canes nearest the centre and take them up to fruit-bearing side-shoots.