Tony Dickerson answers your questions
Q Is there a way to tell the difference between summer and autumn-fruiting raspberries? Sue Tovey, Shurdington, Cheltenham
A This frequently confuses gardeners, especially in a season when the autumn raspberries have fruited earlier in many areas. But it’s actually very simple to tell which is which at this time of year. Summer-fruiting raspberries have long-finished but the old canes will be obvious with the dry stalks from where the fruit was picked. In addition, there’ll be lots of new canes which will overwinter and bear fruit next year. There will only be fruiting and fruited canes on autumn raspberries, as the new canes for next year don’t emerge until February.
Prune out all the fruited canes on summer-fruiting raspberries now at ground level. Don’t leave any stubs. You then need to thin the remaining canes, pruning out weak ones, to leave strong canes spaced 10-15cm (4-6in) apart. With very long canes, loop the top over and tie in to the top wire. You trim these long canes to 10cm (4in) in February above the top wire.
With autumn-fruiting raspberries, you simply cut them to the ground in February, but also thin out some of the canes. This will result in better quality fruit and makes picking easier.
Raspberries are tall plants and need support. If you haven’t got any in place, now’s a good time to get busy. In a small garden, you can drive a 2.1-2.4m (7-8ft) post into the ground and plant up to three raspberries around it. Use similar stakes on larger plots in rows 3.6m (12ft) apart.
A single-post fence system, with horizontal wires running along it, spaced about 60cm (2ft) apart, works well for summer raspberries. Next summer, if you’re clever, you’ll keep the fruiting canes on one side and the new canes on the other, which makes pruning easier. For autumn-fruiting raspberries, which are bushier, it pays to have a double row of post and wires either side of the row, with a gap of about 60cm (2ft).
If you’re planting new raspberries this autumn try to get the support system in place first. The most common mistake is to plant too deeply. The horizontal roots should be no more than 5-7.5cm (2-3in) below the soil surface. Firm plants in and tie to a supporting wire.