Plant blackberries and dark, juicy berries will be your reward for many years to come! Excellent on cereal, as jam or jelly, in a cobbler, or used to make wine, blackberries are an excellent addition to any garden.
Blackberries grow from a perennial root system, putting out new biennial stems (canes) each year. In a blackberry cane’s first year, when it is called a primocane, it will reach it’s full length without producing fruit. In it’s second year, it becomes a fruit producing floricane. The fruit is produced on racemes found at the tip of lateral buds. After the second year, the cane dies, making room for the next year’s crop. Botanically speaking, blackberries are not berries at all. Like raspberries, they are an aggregate fruit made up of small drupelets.
First and second year canes are often covered with numerous sharp prickles, mistakenly called thorns. Prickle-free (thornless) varieties are available. I have heard from several growers that thornless varieties produce bigger fruit, but that varieties with prickles have far better flavor. Personally, I’ll take quality over quantity any day!
There are two basic cultivars of blackberries: erect and trailing. Erect blackberries have stiff canes that arch. While not completely self-supporting, erect blackberries tend to grow into huge thickets if not pruned. Trailing cultivars, also known as dewberries, will spread horizontally across the ground. If you live in a cold area, there are even late-season blackberry varieties that can produce late summer crops. The University of California provides an excellent list of blackberry cultivars.
How to grow blackberries
Blackberries are rugged. In the wild, they grow best near creeks, in alluvial soil. Blackberries can be grown in containers, as long as they are at least 5 gallons in size. Blackberries can be grown in poor soil and will transform an empty lot into a fruit-producing thicket, left unchecked. Blackberries do best in raised beds where drainage and weeds are more easily controlled. To plant your blackberries, follow these tips for the best results:
Pollination is critical for fruit production. If blackberries are being grown indoors, hand-pollination will be needed. To hand-pollinate, simply take a fine paintbrush or Q-tip and touch each flower repeatedly every day until the flower begins to turn brown. To protect your outdoor pollinators and other beneficial insects, avoid using chemical pesticides during bloom.
Blackberry pruning & training
Like other cane berries, blackberries are very low-maintenance once established. After a cane has produced fruit, it can be removed. This cuts down on the thicket effect and it encourages the root system to generate new canes that will produce even more fruit.
First-year canes can be pruned to a manageable size or trained onto a trellis. It is a good idea to wear long sleeves, long pants, and heavy gloves when working with blackberries. Those prickles are sharp!
Blackberries are green when they are red. This old saying reminds blackberry growers that unripe blackberries are red. They become ripe 2-3 weeks later, when the fruits are black, but still firm. Do you know how to tell blackberries and raspberries apart? Hint: It’s not the color. The only way to really tell the difference between blackberries and raspberries is to look at the way the fruit comes away from the torus, or stem. If the torus comes with the fruit, it is a blackberry. If the torus breaks away from the fruit, it is a raspberry.
British folklore warns against picking blackberries after Old Michaelmas Day (Ocober 11) because the devil is said to have spit on them! This tradition has a reasonable explanation in science. As cooler, moist weather kicks in, several types of mold can begin to grow on the fruit which can make it toxic. So, enjoy your blackberries before October 11th and leave the rest for the birds!
Blackberry pests & diseases
As rugged as blackberries are, there are still some pests and diseases to watch for. Deer, birds, and other critters will try to enjoy your harvest before you do. Netting can help, but it’s a pain to take off. Many varieties of caterpillar will also happily munch on fruit and leaves, so monitor plants every few days in spring and hand pick those beasties. You can always feed them to your chickens!
Being close cousin to raspberries, blackberries are prone to many of the same pests and diseases. In either case, watch for signs of these blackberry (and raspberry) pests:
Blackberries may also be infected with the following diseases:
Now, don’t let all those threats to your blackberry crop discourage you from trying this amazing plant. They are only possibilities and blackberries seem to survive against the odds. Even notorious Brown Thumbs have been able to grow blackberries successfully! You can, too!
You can grow a surprising amount of food in your own yard. Ask me how!