Planting: Late autumn and winter is the ideal time, during the dormant season, but avoid doing so if the soil is frozen or very wet. Once in the ground, lop off all the stems down to a few centimetres. In the summer after next, you'll have your first harvest.
It seems that blackcurrants need a sufficiently long cold winter, followed by a warm spring to break dormancy. If the chill is not long enough they think they are still in winter and buds won't break into leaf properly and any fruit ripens unevenly.
Although the average UK winter temperature has risen by only 1C since the 1960s, winters have warmed more than summers. Also a small increase in average temperature tends to give a disproportionately large fall in the number of hours spent below 7C - a common measure of how much winter chilling a crop has had.
However some varieties can get by with less winter chilling than others. You can see the chilling hours requirements for different varieties on the Agriculture and Horticulture Development Board website, which also shows how many chilling hours different regions in the UK experienced last year.
- Ben Hope: popular with home growers. Tolerant of warmer winters and ideal for gardens in the south of the UK.
- Ben Lomond: More suitable for cooler regions as it needs more chilling hours, but flowers later in the year so is less likely to suffer if there are late frosts.
- Ben Lawers: a new variety that has been bred to cope with warmer winters.
Source: news items
