My raspberry plants have produced very few berries this year and some of the stems have died back completely. Should I write them off as a lost cause?
Home-grown raspberries bursting with flavour and freshly harvested from the garden are an utter joy. But while the plants, or canes as they’re properly known, are very hardy and usually relatively easy to grow so long as they’re given fertile, weed-free, humus-rich, free-draining soil and protection from birds, they are unfortunately also prone to a number of viruses that can weaken and eventually kill them.
These can be transmitted mechanically by gardening tools, as well as by aphids or some soil-dwelling nematodes, causing symptoms such as stunted growth, mottling and yellowing of leaves, puckering of leaves, “crumbly” fruit, and poor fruiting.
Let’s start, however, with the growing conditions. Are they as described above? If not, then this could be the problem. Raspberries hate poorly drained soil, for example, which will almost certainly cause dieback. So can a very alkaline soil. If either is the case, then consider building a raised bed and filling it with fertile top soil enriched with well-rotted manure or home-made garden compost.
RM Block
Annual mulches around the base of the plants in spring will help to maintain soil fertility and suppress weed growth, while a few handfuls of a slow-release pelleted organic fertiliser will also help with healthy growth and fruiting.
Bear in mind that raspberry plants also need regular pruning to fruit well, with both the particular technique and timing dependent on whether they’re summer-fruiting or autumn-fruiting varieties (see rhs.org.uk).
However, if your plants have indeed become virused, then you’ll need to carefully dig them up and destroy them, including all parts of the root system, before planting again with new plants in the autumn. Make sure you source their replacements from a reputable garden centre or nursery as certified virus free. It’s also important to plant these in a different area of your garden to minimise the risk of reinfection.
