Why Your Blackberry Bush Won’t Produce Fruit and How to Fix It

If you’re like me, you love blackberry everything – jam, cobbler, pie, glaze, you name it. But good, fresh blackberries have a short season and, if you’re buying responsibly (that is, from a reputable local farmer), they can be expensive.

This expense is for good reason: while blackberries are one of the easier fruits to cultivate, growing and harvesting them is still labor-intensive, especially if you’re not using commercial pesticides and fertilizers.

But you don’t just want pints of local blackberries to enjoy over a summer: you want, nay, need, gallons of them for canning, baking, and eating out of hand. And to achieve this need, without destroying your bank account, you’ve decided to grow your own. Here’s how to do it.

Blackberries, like other plants in its genus (such as raspberries), grow on long stems, or canes, usually in two-year periods. This means the canes are biennial, while the roots of the main plant are perennial (return year after year). In the first year of cane growth, the plant produces no flowers (or nearly no flowers) and, therefore, no fruit, and focuses its energy on rooting and growing a robust cane. In the second year, the same cane (“old wood”) flowers and fruits, and the main plant spreads new canes.

Blackberries have super shallow root systems, and can thrive in many soils, including very poor, rocky soil, and spread and hybridize with other like plants quickly. This is why you’ll see huge thorny brambles on mountainsides and on trails, or even on the outskirts of your own yard near wooded areas. It’s very easy for us to pull up, move, and replant these buggers, and they do it themselves if left alone. Spoooooky.

So, if you plant a cane or two in your yard the first year, you can get many, many more canes and years of blackberries, with minimal work involved. Heck, you can let your whole yard get covered in blackberries within a decade. I don’t recommend it, especially if you’re going with a thorny variety, but you do you, Maleficent.

Despite the name, the “erect” varieties still benefit from some trellising for easy picking and ground upkeep. We have all three varieties growing somewhere on our property, with the second and third planted on purpose, and the first ripping my sleeves as I mow the edges of our land.

Starting Plants: Canes vs. Seeds

It’s much simpler to start your blackberries from canes or nursery plants than from seeds, and you’ll get fruit much faster. You can get bare-root or flowering canes from a nursery. You can also get canes from your neighbor, or pull wild ones from one part of your yard into another. However, I strongly recommend starting your blackberries with nursery plants. Why?

Getting your plants from a reputable nursery means you’ll know the precise variety and characteristics of your blackberry. If you take canes from your neighbor Joe, you’ll probably get blackberries, but they may be hybrids with other nearby plants, or prone to disease. Nursery canes are usually sterile (as in, disease-free) and tend to grow bigger, sweeter fruits. I also really hate thorns, and blackberry picking is already labor-intensive enough without dodging stems that tear up my hands, so I love our thornless varieties that we got from our cool local nursery.

Something to note: your nursery blackberry plants are likely a graft (that is, the blackberry plant is attached to another similar plant to enhance the coolest parts of a blackberry), so if that’s a concern, go ahead and go the wild route. Or just ask about the plant you’re getting. However, I’m a fan of the grafts, if you can’t tell.

Oh, and you can also grow your canes from seeds, although it will take hella longer to do so than from canes, and again, because many blackberry plants are actually hybrids or grafts, you may not even get fruits, or a similar fruit, from whatever blackberry you decided to put in the ground.

Okay, let’s plant these buggers. You’ve got your canes. Now what?

As I mentioned before, blackberries have very shallow roots, so you don’t need to plant them very deep. You do, however, want to clear the planting area of grass and other competing plants, because of those shallow roots. I recommend sheet mulching, and keeping the growing area well-mulched each season, to prevent this competition, as well as tall grass that may hide critters that hang out near blackberries, like mice and snakes.

Plant the canes maybe an inch deeper than the nursery container, making sure the roots are completely covered, but not so deep that the cane disappears. Plant canes 5-6 feet apart, at least, and keep rows 5-8 feet apart.

Blackberries will grow in many different types of soil, even in poor clay soil, but benefit from compost additions, looser soil than clay, mulching, and, most importantly, good drainage. Blackberries will not thrive with wet feet.

Lifting, Pruning, and Cultivating

You’ve successfully planted your main berry brambles, and they’re alive. Hooray! Now what?

In the first year, it’s super important that you do. Not. Let your blackberries produce fruit.

I explain this in more detail in my Pruning post, but the gist is that by pruning the flowers the first year, you allow the main plant focus its energy on establishing good roots, as well as more canes for the coming years. For reference, with good pruning, cutting, and cultivating practices, your blackberry bramble can show this progression:

Okay. You’ve planted your canes. You pruned the flowers in the first year. It’s the second year, and your canes are now bursting with blackberry fruits. Major huzzah!

Your fruits will go from from green and hard, to red and softer, to a dark, nearly black (hence the name) purple and fairly soft.

Blackberries do not continue to ripen after harvest, so be sure to pick fruits that have entirely changed their final color. They also rot super fast on the plant after fully ripening (as in, within a couple of days, and less time when it’s very hot or rainy), so make sure you’re checking your bramble every day for fruit.

Pull berries very gently from the plant (ripe ones should give easily), and try not to disturb the rest of the cane, lest you accidentally knock other berries to the ground, or tear the plant.

Some things to watch out for on and around your blackberries:

• Birds. Oh, how the birdies love berries! You can protect your bramble by draping it with bird netting, which prevents birds from getting to the fruits. We’ve used this before, and it works, but it’s a pain in the butt to remove at the end of a season, as it tangles easily with the growing plant, and it’s not great to throw away. Other solutions are keeping other more attractive crops and leaving them for the birds (this is why we keep the wild blackberries on the edges of our property), and simply beating the winged buggers at their game by harvesting your blackberries early each day.
• Stinkbugs and Junebugs. You’ll run into these guys every time you harvest. They won’t harm you, but they’ll chomp on your berries. I don’t use pesticides or anything with them, and we get a good harvest, so I just kind of live with them and the occasional scream I let out when I pick a junebug instead of a berry.
• Mice and Snakes. Neither of these critters have been a problem for us so far, but they can be if you let the grass around your bushes grow too tall, or don’t pick your berries fast enough before they fall to the ground. (Dropped berries can attract mice, which then attract snakes.) Be sure to wear closed shoes and long pants when harvesting, just in case.
• Yellow Jackets, Wasps, etc. Yet another reason to always wear boots. These buggers will hang out and, in worse cases, build their nests near your bramble if you leave holes and/or lots of berries to rot on the ground. Keep the area harvested and filled in, and always wear protective clothing when picking berries.
• Thorns. If you’ve got a thorny variety, that is. And those thorns can rip through denim, which means they also rip through skin, no problem. I recommend gloves and long sleeves when harvesting berries from thorny canes.

How to Prune Blackberries the Right Way for Bigger Harvests

FAQ

Why are my blackberry bushes growing but not producing fruit?

Failure to set fruit in blackberries is a symptom of one or more virus diseases that affect the entire plant. Diseased plants produce new canes that are more vigorous, with rounded and glossier leaflets than normal. The leaves also develop a brilliant, premature reddening in the fall (Figure 1).

How to get blackberry bush to produce fruit?

Blackberry Production Checklist

Build a trellis (can be done before or within first year of planting). Irrigate on a regular basis. Allow three to four new canes per plant to grow to the top wire. Harvest a baby crop of fruit one year after planting and a full crop two years after planting.

Do blackberry bushes produce fruit every year?

What’s wrong with my blackberry plant?

VIRUSES Can be identified by stunted canes and leaves which are mottled or streaked, usually yellow. Unfortunately there is no cure so all canes should be dug up and burnt. Replanting should occur as far away as possible to prevent the disease spreading to them.