The taste of the first raspberry of summer is a treat cherished by many. On the other hand, freshly picked boysenberries, loganberries and marionberries have delectable flavours seldom experienced except by those who grow their own plants. The fresh berries are so soft that they cannot be shipped so can only be enjoyed fresh off the cane. The good news is they are easy to grow yourself.
Varieties of Cane Fruits
In early spring there is a plethora of boxed, bare-root cane fruits just waiting to be planted. Among the expected raspberry and blackberry hybrids are also a wide range of other cane fruits, such as the above-mentioned boysenberries and marionberries. Despite their many different names, these berries are hybrids of blackberries and raspberries. The additional names were coined by an enterprising nurseryman years ago and in the process confused generations of gardeners who sought out these “wonder” berries thinking them to be exotic species. For example, yellow raspberries are just mutations of regular red raspberries, the only difference is colour.
Cane fruits have two distinct growth habits, some are stiff erect bushes growing 1 to 1.5 meters (4 to 5 feet) tall, while others are trailing vines that must have support to keep the fruit off the ground. Both types share the trait that their canes grow one year, then bear fruit and die the second year. Each summer new canes are produced that will bear fruit the following year. Cane fruits are long-lived, usually bearing fruit for up to 20 years, and are extremely prolific.
Everbearing raspberries, such as the popular cultivar ‘Heritage,’ have the benefit that they produce both an early-summer crop on last season’s growth and a fall crop on the current season’s growth. But the trade-off of this extra crop, is they generally lack the subtle flavour of the summer varieties.
Nearly all blackberries are notorious for their thorny canes, but a few thornless varieties do exist. Being thornless means, they are much easier to work with, but the trade-off is they generally bear smaller and less flavourful crops.
Culture of Raspberries
Raspberries grow best in well-drained soil of pH 5.5 to 7.0 that has been supplemented with compost or manure. Raspberries should never be planted where eggplants, peppers, potatoes or tomatoes have grown within three years, this is to prevent a serious soil-borne disease called Verticillium Wilt. Prepare the soil in your cane fruit patch by digging in well-rotted manure or garden compost a few months before planting time. Also ensure good drainage, since cane fruits will not tolerate the wet conditions present in many of our gardens. If need be, grow them in a raised bed.
If growing in rows, plant red and yellow varieties about 0.5m to 1m (1.5’ - 3’) apart within the row and space your rows 2m to 2.5m (6-8’) apart. Black and purple raspberry varieties should be given a bit more space to grow so plant them 1m (3’) apart with the same spacing of 2m to 2.5m (6-8’) between the rows. If raspberries are to be grown in clumps or hills, space all the varieties 2m (6.5’). Once they are planted make sure to water them in well, then cut the canes down to 5cm above the ground. You are only leaving the stubs to mark the rows until new sprouts appear from below the ground.
Let the young canes of summer-fruiting red and yellow raspberries grow undisturbed until their second spring. In that second spring when the buds begin to show green tips, remove all but two or three healthy canes per foot of row. Hill plants should have all but six to eight canes removed. Then cut back the tops of the remaining canes that will bear fruit to a height of 1m (3’).
While everbearing red and yellow raspberries will bear two crops a year, such production puts a great strain on the plants. It is best to cut the canes of everbearing raspberries to the ground late in the fall instead of spring or early summer, this delay in pruning allows unrestricted summer growth and give the plants much needed energy to produce a heavy fall crop.
To prune black and purple raspberries, snip off the tips of the new canes in midsummer when they are about 1m (3’) tall. This will encourage them to send out laterals, or side branches, which can double the fruit production for the following year. In the spring remove all but three to six strong canes and cut back the laterals to about 20cm (8”). Each of the buds on the laterals will bear several clusters of berries. Cut away the fruit producing canes as soon as they finish bearing.
Culture of Blackberries
The culture of bush and vine types differs considerably, because of their different growth habits.
Bush-type blackberries should be planted 1m (3’) apart within the row and the rows should be spaced 2m (6’) apart. Newly planted bushes should have their canes cut back to 15cm (6”) from the ground. During the summer, mulch with 15cm (6”) of old straw or 10cm (4”) of wood chips, sawdust or ground bark. When the new summer-growing shoots reach a height of 1m (3’), remove the stem tips to force production of side branches.
Late in the following spring, after flower buds appear, remove any weak canes and thin so the canes are at least 25cm (10”) apart. Reduce the length of the side branches to about 50cm (20”). The buds on the remainder of the side branches will produce white flowers, followed by fruit in midsummer. While the previous season’s growth is producing fruit, new stems are growing for another season’s crop, the tips of these canes should be pruned. Late in the summer after the fruiting season has passed, cut out and destroy all canes that have borne fruit, to make way for the next season's crop.
Vine-type blackberries should be treated the same as the bush type in terms of planting, initial pruning to the ground, and mulching. The big difference is that during the first season allow the vines to creep along the ground until they are 2m (6’) long. Then cut off the tips to force the development of side branches. During the summer or early in the following spring, install posts at 5m intervals along the rows and nail two strands of galvanized-iron wire from post to post at different heights. The vines can then be tied to the wires during the summer for support and to raise them off the ground. Each spring cut off all but 16 canes from each plant, and tie them in bunches of four to the wires. Cut back side branches to 30cm (1’), and as with bush-type plants remove all fruit-bearing canes after the season has passed.
Cane-fruit plants should be fed in early spring with GARDENWORKS Fruit and Berry Fertilizer at the rate of 1kg per 2m of row (read the instructions on the container for specifics). For organic gardeners, apply rock phosphate at a rate of 250g per row, and top dress with 2.5cm (1”) of well-rotted manure or garden compost. Dolomite lime applied in April will provide a boost of calcium and balance the pH.
Raspberries are ready for harvest when the berries separate easily from the stems. To pick berries gently pull each ripe fruit between the thumb and forefinger, if it’s ripe it will drop into your hand. Be gentle with the berries, they crush easily so don’t pile them into a deep container. Also try not to wash or wet them, water can start the rotting process and it dilutes their flavour.
Blackberries, tayberries, boysenberries and loganberries should be harvested in midsummer when the berries are so ripe, they drop off at the slightest touch. Unripe berries or those allowed to sit in the sun after picking have a bitter taste.
Red and yellow raspberry plants propagate themselves, spreading by underground suckers. If new plants are not wanted, pull out the suckers. Cutting them off only causes more suckers to grow, so you have to pull them out. To get new black and purple raspberry plants, use the method called tip layering. This is done by covering the tips of the arching stems in the late summer with a shovelful of soil—a new plant will start to root at that spot in the spring. Once this happens you can cut it off from the mother plant, dig up the rooted plant and replant it elsewhere.