Raspberries: leaves, flowers & care
Grown for their jewel-like red berries, raspberries are one of the tastiest and most widely grown soft fruits. Discover all there is to know about raspberries and the basics of growing them at home.
With their sweet and juicy flavour, it is no wonder that raspberries (Rubus idaeus) are one of the most popular summer fruits. Perhaps best eaten fresh on their own, but raspberries can also be used to make delicious desserts, ice cream and jam. Read on to learn all about the raspberry’s origins and how to care for them.
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Raspberries: origin and characteristics
Native to northern parts of Europe and Asia, raspberries have been cultivated for thousands of years and are a member of the Rosaceae family, along with apples (Malus domestica) and blackberries (Rubus fruticosus). As a perennial bush or shrub, raspberries die back and enter a dormant period over the winter before the canes grow anew the following spring. Raspberry bushes can reach 1.8m in height thanks to their robust and upright growth. However, there are also compact raspberry varieties available that are suitable for growing in containers. Raspberry plants are a delightful investment because they can be fruitful for 10 years or more if properly cared for.
Raspberry leaves
Raspberry plants develop three to five oval or lance-shaped leaves on stems that grow alternately from the canes. The leaves are green and are typically serrated and, as winter approaches, they turn orange or red before falling when the temperature drops. Most raspberries, like roses, develop thorns along their canes and stems. Luckily, some raspberry varieties have been bred to be thornless, making harvesting raspberries far easier on the hands. Raspberry leaves can be used to make an herbal tea that is said to help with digestive and inflammatory issues.
Raspberry blossoms
Depending on the variety, raspberry plants blossom between early and late summer. Raspberry flowers are small, typically 0.5 to 1.5cm in diameter, with five petals surrounding the yellow pistils and stamen. Generally white or pink, raspberry flowers produce large amounts of nectar and are loved by pollinators, which makes them great for encouraging bees into your garden.
Raspberry fruit
Raspberry fruits are characteristically red, although some varieties can produce black or yellow fruits. Interestingly, raspberries are not classed as a berry but rather an aggregate fruit. This is because each fruit grows from more than one ovary. Once pollinated, the ovary swells before forming a brown fruit, turning yellow and finally red when fully ripe. Depending on whether you grow autumn-fruiting, summer-fruiting or even the newly introduced double-cropping Twotimer® raspberries, the fruits are ready to pick from June or August. When raspberries are ready to harvest, they are a rich red colour and are easy to pull off from their yellow core. To prevent the fruits from over-ripening and turning soft, check on and harvest raspberries every 2 to 3 days.
Loved by both children and adults alike, raspberries are not only delicious but highly nutritional. As a great source of fibre, raspberries also contain high levels of vitamins and minerals.
Raspberry bush care
Raspberries are vigorous plants, both above and below the ground. Producing strong cane growth from spring onwards, raspberries also sucker from their roots. These suckers can be used to propagate new plants or you can plant raspberries with a root barrier to prevent them from spreading.
Preferring a moist soil, raspberries need sufficient irrigation to support their growth, especially when the fruits are forming. Without adequate water, the raspberries may not develop into the large juicy prized fruits. However, avoid overwatering or growing raspberries on sites that are prone to waterlogging, as this can lead to the roots rotting and other raspberry diseases.
Mulching the soil around raspberry plants can help prevent moisture loss and weeds from appearing. Not only that, but mulching raspberries will also help improve the fertility and structure of the soil. To mulch your raspberries, simply apply a thick layer of garden compost or well-rotted manure around the canes in spring.
As they are hungry plants, it is best to fertilise raspberries to help ensure maximum yields come harvest time. On planting and annually thereafter in spring, apply a slow-release general fertiliser that is high in potassium. Container-grown raspberries can further benefit from extra nutrients later in the season to replace those that have been lost. A liquid tomato food is best for feeding raspberries in pots, as it is easy to apply. Our Plantura Liquid Tomato Food contains the key potassium and phosphorus to encourage flowering and fruiting. Simply, apply the liquid food every 4 weeks when watering as soon as the first flowers appear.
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Supporting raspberries is not essential for the plants to fruit. However, all but the most compact varieties can benefit from staking to prevent the canes from breaking when heavily laden with fruit. Learn more about supporting raspberry bushes using either single or double-row methods in our separate article.
Pruning is key to the health, fruit production and longevity of raspberry plants. The technique and timing of pruning raspberries depend on the variety you choose to grow. Autumn-fruiting raspberries are perhaps the easiest to prune, simply cut them back to near soil level in late winter. Whereas after summer fruiting varieties have finished cropping, prune out the fruited canes and tie in the new growth to fruit the following year.
Overwintering
As winter approaches and raspberry plants lose their foliage and go dormant you can reduce any watering as natural rainfall will suffice. Raspberries are tough plants and being rated H6 for hardiness indicates that they can withstand temperatures as low as -15 °C and the worst of our typical winters. However, you can add a layer of fleece or mulch to less than one-year-old plants to help insulate their roots against the worst of the cold. Container-grown raspberries are more susceptible to a hard frost. Cover raspberries in pots with fleece or move them under a porch or to the lee of a wall to give them some protection over winter.
With raspberries being so delicious, you may find you want to grow many raspberry plants for an even bigger harvest. Thankfully, it is easy to propagate new raspberry plants; find out how in our separate article.
