How to Grow Blackberries

The rubus species of flowering bramble bushes, better known as blackberries, are an aggregate fruit that have spawned over 375 species. Blackberries can be found growing wild in Europe, northwestern Africa, western and central Asia, South America, and North America. Each region has its own indigenous subspecies, and blackberries can be cultivated in sunny, temperate regions worldwide.

Blackberries are a hardy bramble that should be planted in USDA hardiness zones 4-9. They’re recommended for intermediate gardeners and produce healthy fruit for up to fifteen years after they’re planted. These brambles will grow well with loamy, well-drained soil, direct sunlight, and plentiful water. 

Erect blackberries support themselves, making care a bit less strenuous for novice gardeners. The trailing varieties have long canes that must be trellised for support, adding a bit more labor to planting your crop than other varieties. But the trailing varieties are well-known for their sweet, juicy flavor, and they are worth the extra elbow grease to grow.

Blackberries are amazing, soft, sweet and tart berries which are popular for use in desserts, jams, jelly, and even wine. Blackberries are also a baker’s delight. They are not difficult to grow and maintain, and with a little know-how you can enjoy these sweet fruits for years to come. 

About Blackberries

Blackberries are members of the Roseacea family which contains over 2500 plant species. The Roseacea family is a flowering plant family with four major subfamilies. Blackberries fall under the subfamily Rosoideae along with roses, strawberries, and lady’s mantle, to name a few. They are then classified under the genus Rubus, which is the proper name for all brambles. These include raspberries, loganberries, and boysenberries as well as blackberries.

There are three basic types of blackberries:

1. Erect thorny blackberries
2. Erect thornless blackberries
3. Trailing thornless blackberries

While wild blackberries grow in a variety of places between USDA hardiness zones 3-10, it is recommended to cultivate blackberries in USDA hardiness zones 4-9. These areas will support a healthy crop that will grow for years to come.

Unlike many other varieties of fruit, blackberries and all their hybrid offshoots are self-fertile using their own pollen and not dependent upon opposite sex plants in order to pollinate. But the flowers do require pollinators, such as bees and butterflies to spread the pollen for them. 

Growing Blackberries From Scratch

Blackberries grow plentiful out in the wild, but they are also popular in gardens and grown commercially.

It’s fairly easy to get your new blackberry brambles growing. You can either start from a simple seed, or you can plant an existing root or juvenile plant directly into healthy soil.

While it’s far easier to grow blackberries from a clipped root from a healthy plant or from a juvenile plant from a nursery, you can grow blackberries directly from the seed. It just takes a little more work and know-how.

The process of growing from seeds extracted from blackberries takes a bit of time and effort, but it can be very rewarding. Growing blackberries directly from the seed will not produce fruit in the first year, so this method also requires a lot of patience. 

Separating seeds from blackberries is fairly easy. Simply place healthy, ripe blackberries into your blender or food processor and pulse until the fruit and seeds pull apart. Then pour the mixture into a strainer fixed with a coffee filter, tea towel, or cheesecloth to remove the juice. After the pulp has dried a bit, carefully use your tweezers to pull the seeds out. 

Then, once removed from the pulp, your seeds should be sandwiched between some peat moss either in a sealed sandwich bag or in a plastic container covered with a damp paper towel. Place your peat moss and blackberry seeds in a refrigerator with temperatures between 33-35° for three to five months, keeping the peat moss moist at all times. 

Once the seeds begin to open up, you can transfer them into a pot with good drainage. Plant the seeds in fruit-friendly soil and mix in some high-grade fertilizer.

Care from seed to berry is a long process that takes calculated effort and requires temperature-controlled conditions. Not every gardener has the time or equipment to nurse seedlings. The easiest way to get started growing blackberries is to purchase a bare root or a young plant from a nursery which can be planted directly into the ground. 

Caring for your blackberries

Blackberries grow best under the right conditions. That means selecting the right soil, the best spot for adequate sunlight, and a location close to a water source. Brambles must be spaced appropriately when planted, and some varieties must be trellised in order to grow upright. Pruning throughout the season is also recommended to keep blackberry plants growing healthy all year long. 

Soil

While blackberries can grow in almost any soil, the optimal conditions are loam or sandy loam soils that have good drainage. The soil surrounding young blackberry plants needs to be kept moist. It is also recommended that you mix in fresh fertilizer monthly. 

The pH levels optimal for growing blackberries ought to be between 5.5-6.5. The soil should also be rich with organic matter to ensure the best growing conditions. Completely neutral soil has a pH of 7.0. So if your soil needs more acidity to grow the best blackberries, you can mix in composted cow manure to even out the acidity. Soil that is too acidic will grow beautiful leafy greens, but it will leave you with little to no fruit on your brambles. 

Water

Blackberries need plenty of water, and they enjoy growing in moist areas with good drainage. A proper irrigation system nearby is essential to growing loads of healthy blackberry plants. For a gardener growing a small blackberry harvest at home, make sure you water with running water from your hose often enough to keep the plants healthy. If you are experiencing lots of rain, you may not need to water as often. 

When planting your starter roots or juvenile plants, make sure to water thoroughly. After about three weeks of growth, make sure to water your blackberries plants during daylight hours. They will need approximately 1″-2″ per week during growing season and up to 4″ per week during harvest. Blackberry brambles are shallow rooted, so moisture needs to remain near the surface to keep them healthy. 

Sunlight 

While blackberries prefer conditions with direct sunlight for eight or more hours per day, blackberry plants can also grow beautifully in partial shade. However it is recommended for gardeners who want a bountiful harvest to plant in sunnier areas. Blackberries growing in shady conditions tend to produce less fruit. 

Spacing

Trailing blackberry plants should be spaced about 10 feet apart in the row. This allows the plants to grow about 5 feet in either direction. Spacing for erect plants, not trellised and maintained about 3 feet tall, would be about 3 feet apart. 

Pruning

Tip pruning should take place in the spring before your flower buds form. Cut off the tips of the blackberry canes to force the canes to branch out. Use sharp, clean pruning shears to cut the canes to about 2 feet in length. If the canes are shorter than that, simply cut off the top inch. During springtime pruning, also cut off any diseased or dead canes to keep your blackberry plants healthy. 

Seasonal Care of Blackberries 

All blackberries are perennials. While the roots survive for multiple years, the top of the plant above the soil is biennial. This means that you will see fruit once every two years.

The first year, a new stem grows to its full length, arching or trailing along the ground and bearing lush leaves with five or seven leaflets. It will be a beautiful, healthy bush, but no flowers or fruit will bloom. The second year, the stem does not grow longer, but the flower buds open. You may see smaller leaves in the second season, but don’t despair. Your blackberry plant is healthy as long as it flowers. 

Like any other plant, blackberries vary in care from season to season between growth and dormancy. And care is crucial during each season to keep your plant thriving. 

Spring 

Plant your blackberries in the spring. It is recommended to plant the canes anywhere from three to ten feet apart. Simply dig a hole in your soil just deep enough to contain the full soil from your well-drained pot containing your blackberry plant. Then cover your juvenile plant with the loose soil from the earth and water thoroughly. Depending on the type of blackberries you are growing, a trellis or stakes may be necessary to keep your blackberry plants erect.

During the fruiting years, your flowers will bloom in late spring. Healthy blackberry flowers are a light, whitish-pink color. 

Summer 

Also in the fruiting years, your berries come alive. This is what you have been waiting for when you started out with a juvenile plant, a clipped root, or a simple seed. 

Blackberries will begin to ripen in July and August, but early bloomers may pop out as early as late June. For the best flavors, it is important to pick ripe blackberries. You can tell they’re ripe when they are dark black in color and plump. If the berry is a light purple or red or is quite firm, it’s not yet ready. Let it remain until it is softer, thicker, and darker in color. 

Autumn

Fall is the typical season for pruning blackberries. After your blackberries are done producing fruit in the late summer, prune out all floricanes. The floricanes are your canes that produced flowers and fruit that year. Since blackberry canes are biennial, once a floricane is spent, it won’t produce fruit again. Cutting off floricanes encourages the bush to grow more primacanes, which will mean more fruit in the coming year. Always use sharp, clean pruning shears when pruning your blackberry canes.

Winter

If your blackberries are of the erect variety, prune your canes in late winter. Remove all of the weaker canes of each plant, leaving only the three or four strongest canes standing. 

Winterizing blackberries is different for trailing types and erect types of berry bushes. It also differs per climate region. Some may need to be removed from their stakes or trellises and covered in dark mulch to keep from succumbing to harsh winter frost.  Erect canes are more hardy and survive cold winter months better. 

Blackberries in the Wild

As an avid forager, finding blackberries among the edge of the woods along hiking paths is one of the greatest thrills. You can find these sweet berries growing wild in many areas of the US and worldwide. While some of us are lucky enough to find Allegheny blackberries growing rampant nearby our homes, others may have to travel off the beaten path to find these hidden gems. This particular species of blackberry nurtures new tree growth, just as long as the critters, such as deer, stay away. When you find Allegheny blackberries growing healthy along the edge of the woods, you will know they are helping the ecosystem around them.

Blackberries grow wild in many parts of the world. Their origins are mostly unknown. However, scientists have found evidence that blackberries had grown wild in Asia, Europe, and Africa before the Iron Age. Blackberries were eaten and otherwise used by ancient cultures all over the world. Native Americans used the berry for food and dye. The ancient Greeks believed that blackberries could cure gout. And the Anglo-Saxons baked primitive pies with the berries while using the thorny bushes to keep dangerous animals at bay. 

Once, blackberries were believed to only be wild and that cultivation of the brambles wasn’t possible. Until the late 1800s, cultivation of the brambles was not even attempted. 

Fun Facts

Watch out! Many varieties of blackberry have thorns just like roses. Since they come from the same family, this is no surprise. Thornless varieties were bred in the late 19th and early 20th centuries. 

Zweeloo Woman was a mummified bog body discovered in Drenthe, Netherlands in 1952. She had died before BC turned to AD. Scientists discovered that she had remains of millet porridge and a lot blackberries in her digestive system.

Blackberries are a superfood. The health benefits of blackberries include better digestion, strengthened immunity, increased heart health, and a number of cognitive benefits including improved memory.

Blackberry pie has been enjoyed by families like yours for a very long time. Fannie Farmer printed a blackberry pie recipe in the Boston Cooking-School Cookbook in 1896 to much acclaim.

National blackberry day is September 12, while national berry month is July. 

Article sources:

• University of Kentucky
• University of Florida