Blackberries are one of the easiest fruits to grow, but that doesn’t mean they’re mistake-proof.
Many gardeners dive into blackberry growing with big dreams of plump, juicy berries, only to end up with weak plants, poor harvests, or even a berry patch that gets out of control.
The good news? Most blackberry-growing mistakes are easy to avoid—if you know what to watch for.
Whether you’re a beginner or have been growing blackberries for years, understanding these common pitfalls can save you time, frustration, and even your harvest.
Let’s dig into the biggest blackberry-growing mistakes so you can grow a thriving berry patch and enjoy sweet, homegrown fruit year after year.
Planting Blackberries in the Wrong Spot
Blackberries may be tough plants, but that doesn’t mean you can plant them just anywhere and expect a bountiful harvest.
If you plant blackberries in the wrong location, you might end up with weak plants, small berries, or no berries at all.
Choosing the right spot from the beginning can make all the difference.
Too much shade means fewer berries.
Blackberries love the sun.
They need at least six to eight hours of direct sunlight every day to produce well.
If you plant them in a shady spot, your blackberry plants may grow, but they won’t thrive.
They’ll become leggy, weak, and won’t produce as much fruit.
Even worse, berries that do grow in shady conditions may be smaller and less flavorful.
If your blackberries are struggling, take a good look at their location.
Are they getting enough sunlight, or are trees and buildings blocking their light?
If shade is the problem, you might need to move them to a sunnier location next season.
Poor drainage can lead to root rot.
Blackberries like moist soil, but they hate standing water.
If you plant them in a spot where water pools after it rains, your blackberry roots could rot.
Once the roots start rotting, there’s no saving the plant.
The best way to avoid this is to plant blackberries in well-draining soil.
If you have heavy clay soil, consider raising your planting area by creating a mound or planting them in a raised bed.
That way, excess water can drain away instead of sitting around the roots.
Planting too close together can lead to problems.
Blackberries grow fast, and they spread.
If you plant them too close together, they’ll compete for sunlight, water, and nutrients.
Crowded plants also create a humid environment, which is perfect for mold, mildew, and other plant diseases.
Give your blackberry plants plenty of space.
Most varieties need about three to five feet between each plant and eight to ten feet between rows so air can flow freely.
Good airflow helps keep plants healthy and prevents disease from spreading.
Not testing the soil before planting can lead to issues.
Blackberries aren’t too picky about soil, but they do best in soil with a pH between 5.5 and 7.0.
If the soil is too acidic or too alkaline, your plants won’t absorb nutrients properly.
A simple soil test can tell you the pH of your soil.
If your soil is too acidic, adding lime can help.
If it’s too alkaline, adding sulfur can bring it back into balance.
Getting the soil right from the start will give your blackberries the best chance to grow strong and produce lots of fruit.
Forgetting to Prune at the Right Time
If there’s one mistake that can turn a healthy blackberry patch into a tangled mess, it’s forgetting to prune at the right time.
Blackberry plants need regular pruning to stay productive.
Without it, they’ll grow wild, produce fewer berries, and become harder to manage.
The good news is that pruning isn’t complicated, but timing is everything.
Pruning matters because blackberries grow on biennial canes.
This means that each cane grows for two years.
In the first year, the cane is called a primocane—it grows leaves and stores energy.
In the second year, that same cane is called a floricane—this is the one that produces berries.
After the floricane produces fruit, it dies.
If you don’t prune out the dead canes, your blackberry patch will fill up with old, useless growth that takes up space and blocks new growth.
There are two important times to prune blackberries—after harvesting and in early spring.
Summer pruning should happen after harvesting.
Once a cane has finished producing berries, cut it down to the ground.
This makes room for new canes to grow and keeps your blackberry patch from becoming overgrown.
Removing old canes also reduces the risk of disease since dead canes can attract pests and fungi.
Spring pruning should happen before new growth begins.
In early spring, look for the strongest canes and trim off the top few inches.
This encourages side shoots, which means more fruiting branches for the next season.
Remove any weak or damaged canes to keep the plant healthy.
Not pruning leads to tangled, unproductive plants.
If you skip pruning, your blackberries will become a tangled jungle of old and new growth.
This can cause several problems.
Fewer berries grow because the plant wastes energy on unproductive canes.
More disease spreads due to poor airflow.
Harvesting becomes harder because the berries are buried under thick, thorny growth.
Pruning may seem like extra work, but it’s one of the most important things you can do for your blackberry plants.
By keeping up with it, you’ll have healthier plants, bigger harvests, and an easier time picking your berries.
Ignoring Proper Watering and Feeding
Blackberries may be tough, but they still need the right balance of water and nutrients to thrive.
If you neglect watering or don’t feed your plants properly, you might end up with small, dry berries—or worse, no berries at all.
Getting these basics right can make the difference between a weak plant and a bountiful harvest.
Watering too little can lead to shriveled berries and weak plants.
Blackberries need consistent moisture, especially during hot weather and when they’re producing fruit.
If they don’t get enough water, their leaves will start to droop, and the berries may stay small or dry out before they fully ripen.
A good rule of thumb is to provide at least one inch of water per week.
During hot, dry spells, they may need even more.
Instead of shallow watering, which only wets the surface, soak the soil deeply so the roots get the moisture they need.
Adding a layer of mulch around your plants can help retain moisture and keep the roots cool.
Watering too much can drown the roots and invite disease.
While blackberries love moisture, too much water is just as bad as too little.
If the soil stays constantly soggy, the roots can rot, and fungal diseases can spread.
To prevent this, always plant blackberries in well-draining soil.
If you’re unsure whether your plants need water, check the soil with your finger.
If the top inch is dry, it’s time to water.
Forgetting to feed your blackberries can lead to weak growth and poor fruit production.
Blackberries aren’t heavy feeders, but they do need nutrients to stay strong and productive.
If your plants seem slow-growing or produce small berries, they may be lacking nutrients.
The best way to feed them is by using a balanced fertilizer in early spring, just as new growth appears.
Look for a fertilizer labeled 10-10-10 or something similar, meaning it contains a good mix of nitrogen, phosphorus, and potassium.
Too much fertilizer can do more harm than good.
It might seem like more fertilizer means more berries, but that’s not always the case.
If you overfeed your blackberries, especially with too much nitrogen, they’ll produce lots of leafy growth but fewer berries.
Stick to feeding them once in early spring and again after harvesting to help the plants stay strong for the next season.
If you want to go the natural route, compost or aged manure can provide a slow-release source of nutrients that helps blackberries thrive without the risk of overfeeding.
By watering properly and providing the right nutrients, you’ll keep your blackberry plants strong, healthy, and loaded with delicious fruit.
Letting Pests and Diseases Take Over
Blackberries are hardy plants, but that doesn’t mean they’re immune to pests and diseases.
If you ignore the warning signs, problems can quickly spiral out of control, leaving you with damaged plants and disappointing harvests.
Keeping an eye on your blackberry patch and taking action at the first sign of trouble can save your plants and your fruit.
Pests like beetles, aphids, and worms love blackberries as much as you do.
Some of the most common pests include Japanese beetles, spider mites, aphids, and fruit worms.
Japanese beetles chew on the leaves, leaving behind skeletonized foliage.
Spider mites suck the juices from leaves, causing them to turn yellow and dry out.
Aphids cluster on the undersides of leaves and stems, spreading disease as they feed.
Fruit worms burrow into berries, ruining them before you get a chance to pick them.
To keep pests under control, check your plants regularly.
If you see a few beetles or aphids, handpick them off or spray them with a blast of water.
For larger infestations, insecticidal soap or neem oil can help without harming beneficial insects like bees.
Diseases like fungus and mold can ruin a healthy blackberry patch.
Blackberries are prone to fungal diseases like powdery mildew, gray mold, and cane blight.
Powdery mildew looks like a white, powdery coating on the leaves.
Gray mold causes berries to rot before they ripen.
Cane blight leads to dark, dead-looking areas on stems, weakening the plant.
Most fungal diseases thrive in damp, crowded conditions.
To prevent them, make sure your plants are spaced properly so air can circulate.
Prune regularly to remove old, dead canes that can harbor disease.
If you notice signs of fungus, remove affected leaves or canes and dispose of them away from your garden.
Applying a fungicide or a homemade solution of baking soda and water can help slow the spread of disease.
Ignoring pest and disease problems can ruin your harvest.
If left unchecked, pests and diseases can quickly take over, leading to fewer berries and weaker plants.
A little prevention goes a long way.
By keeping an eye on your blackberry plants, maintaining good airflow, and using natural or organic treatments when needed, you can keep your blackberry patch healthy and productive all season long.
Not Controlling Blackberry Spread
Blackberries are delicious, but they can quickly turn from a well-behaved berry patch into an out-of-control jungle.
If you don’t take steps to control their spread, they can invade your garden, crowd out other plants, and become difficult to manage.
While blackberries are known for their fast growth, you can keep them under control with the right strategies.
Blackberries spread aggressively through underground runners called suckers.
These suckers pop up away from the main plant, creating new blackberry canes.
If left alone, they can quickly take over an entire area, creeping into your lawn, flower beds, or even your neighbor’s yard.
To prevent this, keep an eye out for new suckers and remove them as soon as they appear.
Dig them out with a shovel or prune them at the base to keep them from spreading too far.
Choosing the right blackberry variety can help reduce the problem.
Some blackberry plants, known as trailing varieties, stay more contained, while others, called erect or semi-erect varieties, spread aggressively.
If you want a more manageable blackberry patch, choose a variety that fits your space and doesn’t send out runners as aggressively.
Installing a physical barrier can stop blackberries from spreading beyond their designated area.
A simple way to do this is by sinking a barrier, like metal or plastic edging, at least a foot deep into the soil around your blackberry patch.
This helps block the underground runners from sneaking into other parts of your garden.
Regular pruning is one of the best ways to keep blackberry plants in check.
By cutting back old canes and thinning out new growth, you’ll not only prevent overgrowth but also encourage healthier plants and better fruit production.
Blackberries may be fast growers, but they don’t have to take over your garden.
With a little effort, you can keep them contained and still enjoy plenty of fresh berries.
Final Thoughts
Growing blackberries is rewarding, but avoiding common mistakes will make the experience even better.
By choosing the right location, pruning on time, watering and feeding properly, keeping pests and diseases in check, and controlling their spread, you’ll set yourself up for success.
A little planning and maintenance go a long way in ensuring a healthy, productive blackberry patch.
With these tips, you’ll enjoy sweet, homegrown blackberries season after season.