Blackberries are usually big plants and unsuitable for pots, but the thornless varieties are less vigorous and can be successfully grown in a large container. They are amenable plants and can grow well in sun or in partial shade.
When to plant: Autumn.
At their best: Late summer to early autumn.
Time to complete: 1 hour.
You will need: Blackberry plant, ‘Loch Maree’ (for example), large pot, soil-based potting mix, broken clay pot pieces, stakes or trellis for support.
Plant up and feed
Place the clay pieces in the bottom of the container to aid drainage and to prevent the holes from blocking up. Fill with soil and plant. Most soil contains enough nutrients for the first few months, but in summer in subsequent years apply a tomato feed every week to promote flowering and fruiting.
Tie in stems
Blackberries produce long growths that need tying in. Insert a few strong stakes into the soil, or place the container up against a sturdy trellis. When tying, create a “figure-eight” so that the stem does not make direct contact with the support, which could lead to rubbing and the creation of wounds.
Pruning and care
Blackberries always fruit on the previous year’s stems. Therefore, just after you have harvested your crop, remove any stems that have fruited by cutting them at their base. Tie any new stems into the supports; these should fruit the following year. Replace the top layer of potting mix every spring.