Raspberry growing in Blairgowrie was the origin of the Scottish soft fruit industry, and it is true that they grow particularly well here due to the unique combination of soil and climate. Because of this we manage to produce that combination of wonderful flavour and juiciness that gives them their reputation as one of the real luxuries of summer. When you also consider the array of phytochemicals they contain that are associated with so many health benefits as well as claims of aphrodisiac properties, it is no wonder they are such a favourite fruit. Modern varieties and growing techniques have overcome some of the problems they had such as a sometimes sharp edge to their flavour, and a very short shelf life, so that you can expect to enjoy raspberries all season.
Traditionally, raspberries ripened in Scotland from early July until mid August, but as with strawberries, we have extended the season using new varieties and techniques. There are two types of raspberry, summer fruiting or autumn fruiting. We used to grow only summer fruiting types, which grow canes one year and then bear fruit on that cane the following year, while also growing next year’s canes. Because the cane has been grown the previous year, only the fruits have to be produced, so these are the earliest into production in early summer, but only have a season four or five weeks long. The autumn fruiting raspberries manage to grow the cane and also carry fruit on that cane in the same year. They are later into production as they have to start from the ground, but they do keep cropping until autumn frosts finally stop them. We can now start in early June with closed tunnels, and pick continuously until early October, when the autumn fruiting varieties start to become too soft in the cooler, duller days.
Summer fruiting raspberries
- Glen Ample This variety was bred locally near Dundee, and is just one in a long line of outstanding varieties from the Scottish Crop Research Institute. It has large, good tasting, firm fruits, and was a real winner when it appeared 15 years ago, as it was so much better tasting and better looking than the varieties that were growing at the time.
- Tulameen This variety has a superb flavour that people who know will search out. It also has large, attractive fruits, but they tend to be soft so it is very difficult to get the balance right when picking. Early picking will get firm fruit that perhaps lacks flavour, whereas later picking allows the fruit ripen for fuller flavour, but no-one will get to taste, because the fruit will be too soft to eat. It is also expensive to grow and pick, so it has to be sold at a higher price.
- Octavia This is one of the latest summer fruiting raspberries, it produces large fruits which taste good, but they can occasionally lose some of their flavour in dull weather. Its canes are very thorny, so it is not a pickers favourite. We usually start picking it in mid July, and it lasts until late August.
Autumn fruiting raspberries
- Driscoll’s Cardinal Autumn fruiting raspberries are only just viable in Scotland, even with tunnels, as they tend to start ripening too late and produce too small a crop before the winter cold starts. This is one of the earliest of the autumn fruiters and does well here. It comes from the American Driscoll’s breeding programme, and is noted for its flavoured, well-shaped fruits. We begin picking it in early August, but most fruit comes in September.
- Driscoll’s Maravilla This variety is the most widely grown round the world as it produces a vast crop of large, bright, firm fruits. Unfortunately, it is too late to work well in Scotland, so we only grow a small amount. It can also crop in the early summer of the following year if the canes are left over the winter, and it then provides some good early fruit in June.
We grow all our raspberries in the soil rather than pots, and under polytunnels. Raspberries are very prone to disease in wet weather – botrytis, grey mould and root rot can be very damaging, making the fruit unmarketable or killing the plants completely. Polytunnels keep the rain off and reduce these problems considerably. They also protect the fruit from high winds which is important as even a gentle summer breeze can damage the skin of the fruit. Most importantly, the tunnels allow us to pick whatever the weather, which is especially important for raspberries which often need to be picked every day. One wet day in the open can mean the next day the fruit has to be cleared for processing to allow fresh fruit to ripen. Since rain is recorded on more than half the days in July, without tunnels, it could mean that we would lose most of the crop.
Our fields of summer fruiting raspberries are established using long canes cold stored until April. We plant on small ridges to keep the roots dry, then erect posts and wires to hold the plants. They start cropping in August and the season lasts a month. At the same time as growing the fruit, the plants are also growing next year’s fruiting cane. We cut out the old fruiting canes in the winter, and tie the new canes to the wires. These new canes burst bud in April, and if spring frosts do not kill the flowers, they start ripening fruit in June or July, depending on how well sealed we keep the tunnels.
The autumn fruiting raspberries are easier to manage as they only have one type of cane growing at a time. However, they can be troubled by more pests, as they have a longer season where they need to be protected. The fields are usually established with roots in late winter, which produce a small crop on the young canes in the autumn, but we have to wait until the second year for a full crop. The canes can be quite tall, and because they are growing all the time, we cannot tie them to supports, so we grow them through netting and this supports the canes to allow easy harvest.