Gardening Articles: Edibles :: Small Fruits & Berries
Blackcap Brambles (page 2 of 3)
by Lee Reich
Rule number one in growing black raspberries is: Don't do what I did! When I put in my first planting, I dug nearby wild blackcaps, then set them in a row with my collection of red raspberries. Not only are wild blackcap likely carriers of disease, but the red raspberries may be symptomless carriers of mosaic virus, which aphids can spread to nearby black raspberries.
Instead, purchase nursery-grown plants -- they're much less likely to carry diseases than wild plants are. Few nurseries can officially certify their plants to be virus-free because symptoms are not always obvious and there is not yet a convenient test that determines whether or not plants are infected with mosaic. But researchers are developing a virus test, so that in the future, virus indexing and tissue culture propagation can ensure disease-free nursery plants.
Plant blackcaps as far away as possible from red raspberries or other cultivated brambles, and remove existing wild berries if practical, or your new plants may soon pick up diseases. Black raspberries are susceptible to Verticillium wilt, so also avoid planting where other hosts of this soilborne disease -- such as brambles, tomatoes, peppers, potatoes or eggplants -- recently grew.
When choosing a site, pay attention to sunlight and soil. A sunny site promotes sweeter fruit and quicker drying of leaves, canes and fruits, which helps thwart fungal disease. The soil itself must be rich in humus and well drained, with a pH of about 6. One quarter pound of 10-10-10 (or another fertilizer with an equivalent amount of nitrogen) per plant will get young blackcaps off to a good start. A third of a pound of soybean meal is a good organic alternative. Spread the fertilizer evenly over the surface of the planting bed and work it in shallowly. Most of the roots of black raspberries grow in the surface layers of the soil, so blanket the ground with a thick organic mulch such as leaves or straw.
Space plants three feet apart in the row, with eight feet between the rows. Right after you plant, lop all canes back to the ground, just in case they have any diseases on them. You don't have to worry about plants spreading underground like red raspberries, because most nblack raspberry shoots arise right at the base of the plant. Black raspberries do spread in their own way, however. They take root wherever the tips of arching canes reach down and touch the ground. Don't allow those tips to root unless you want to propagate new plants.