What happened to my Trailing Blackberry's Blackberries?!

I've been "cultivating" the native blackberries of my area. By cultivating, I mean I cut out the invasive blackberries, prune the tips of the native ones, and weave the native berries together up structures and brush. Last year I noticed some of my berries simply did not develop. They flowered, but just made little brown berries. I noticed the same thing happening on some of the other native blackberries on my property that I hadn't managed atI thought it was because I hadn't been pruning the tips to make them focus their energy on berry production. So, this year I pruned the tips, but the same thing is occurring, destroying a good 50-80% of my berries. Is this a mite or a virus? What can I do to prevent this from happening next year? If I just wait and see what happens, will natural predators take over or more resistant berries take over via "survival of the fittest"? Or do I need to plant something to attract natural predators or increase it's resistance? Or do I need to just try to remove all the bad canes? Any ideas? Thank you so much!

Here's some pictures, from two different blackberry patches. Last year, this whole patch was full of gorgeous, big, juicy berries. This year, there are pretty much none!

We've observed the same thing here. Last spring we got really excited because there were tremendous numbers of flowers on the trailing blackberries at the bottom of the yard. Come summertime though... nada. Just like your pictures.

Some, elsewhere, do fruit, and they're delicious, hence the excitement.

They're dioeocious, and I think the "duds" are the flowers of male plants. If you don't have to make fruit, you can put a lot of energy into flowers, hence the phenomenon of the most impressively flowered patches amounting to nothing. They're important though, since you need them to pollinate your fruiting females. I'm not sure of this, it's just the conclusion I came to and seems to make sense.

I can't tell for sure from the pictures, but it looks like the same problem we've observed on our cascade berries, which are a blackberry hybrid.

I do not think this is a case of a male plant, because the same vine would yield some successful berries. Am I correct that this is the same in your case, Nicole?

I also saw the same thing on himalayan blackberries, but attributed it to lack of water, as we treat those as a weed. The cascades were well watered, yet multiple years in a row failed to yield well as a significant portion of the flowers would appear to set fruit, then shrivel to nothing. We waited it out a few years in hopes it was a bad year, too little water, something they would recover from, etc... no joy.


Last year I ripped out the cascades except the largest two volunteers, which I moved to the far edge of the garden. We planted tayberries in their place. Right now the tayberries are yielding well with no significant incidence of this problem; the relocated cascades are still yielding sparsely with this same problem. This might be too early to conclude that the tayberries are safe from whatever the problem is, though...

The raspberries immediately next to this spot have never shown this particular symptom, though we are now losing plants to disease as the patch is probably 20 years old.

Yes, the vine does not make successful berries. Some of the bad vines have one or three berries on them, but those often have dryberry or redberry (part of the berry does not develop and is brown, or it part of it stays red rather than ripening all the way).

It's nice to know I'm not alone. Hopefully together we can figure out what's going on with our blackberries and find a way to safely nip this problem in the proverbial bud!

I wonder if this is down to lack of pollinators - have you noticed a lack of bees in your area?

Can't speak for Nicole, but we've got tons of pollinators here. The woods are abuzz April through September, at least.

Roberta Wilkinson wrote:Can't speak for Nicole, but we've got tons of pollinators here. The woods are abuzz April through September, at least.

The same here. Especially with this oddly warm non-winter, we have had lots of bees, and they came early. They were out and about once the dandelions were blooming, and that was quite a bit before the blackberries bloomed (I can't find my journal, or I'd say the exact day). I personally saw bees happily buzzing on those blackberry blossoms.

Ditto, tons of bees, and they were all over the blossoms for the berries in question...

All the diseases that I've looked up which mention damage to fruit seem to involve molding/rotting, not desiccating to pathetic brown husks. If it was a pest such as a dryberry mite, I would expect to see some partially desiccated berries, which I haven't observed in any notable quantity...

I've noticed this happening when winters are too warm. I bought some experimental berries that shouldn't even be in my zone, need much more cold, and I only get dead, hard balls instead of berries. And be sure your soil is on the acidic side.

I've had good luck with trailing Siskiyous, they've done well when there is a cold snap, and in these past two warm winters. I also have acidic soil.

Hm, that's an interesting thought, but if true would indicate that the native trailing blackberries(Rubus ursinus, for clarity) are *very* sensitive to climate change, since this is their home territory. As for my 'Cascade berries', the theory is they are a cross between Loganberry and Rubus ursinus... and one of Loganberry's parents was also Rubus ursinus, so it makes sense that they share many traits.

Rubus ursinus *is* dioecious, but as long as the same cane is producing some actual berries as well as the husks, this doesn't seem like the whole answer...

I checked with the lady running this site http://www.garden-blessings.com/Pages/CascadeBlackberryPlants.aspx

She hasn't had this problem on any of her cascade berry canes; in fact, she says she gets 10 flats of berries from 8 mature plants, which is ludicrously better than ours have ever managed. So it certainly appears to me that this is a problem with my site or plants, rather than just the way things are for this cultivar...

Dillon Nichols wrote:Hm, that's an interesting thought, but if true would indicate that the native trailing blackberries(Rubus ursinus, for clarity) are *very* sensitive to climate change, since this is their home territory. As for my 'Cascade berries', the theory is they are a cross between Loganberry and Rubus ursinus... and one of Loganberry's parents was also Rubus ursinus, so it makes sense that they share many traits.

Rubus ursinus *is* dioecious, but as long as the same cane is producing some actual berries as well as the husks, this doesn't seem like the whole answer...

I checked with the lady running this site http://www.garden-blessings.com/Pages/CascadeBlackberryPlants.aspx

She hasn't had this problem on any of her cascade berry canes; in fact, she says she gets 10 flats of berries from 8 mature plants, which is ludicrously better than ours have ever managed. So it certainly appears to me that this is a problem with my site or plants, rather than just the way things are for this cultivar...

She also appears to be in Longview, Wa. If I'm not mistaken, that's a very mild, maritime area, so her winter would have been even milder than ours. Maybe it's a combination of a mild winter not killing off some sort of pest (which I can't seem to identify), as well as plant spacing? She has one plant per trellis, and the trellises are well spaced. Maybe it's the crowding of plants that leads to the crop failure? i know that the ones that seem to be failing the most are in pretty crowded plantings, especially since I'm pretty much just encouraging wild growth. Maybe they're missing a nutrient? I really wish I knew!

I think I might try making a nettle/horsetail fungicide/insecticide and applying that to my bramble and seeing if that helps. But, would the nettle insecticide keep bees away? I have so many questions and so little knowledge!

Oh, and you're right about it not simply being with the cultivate. Certain areas where the flowers didn't turn to withered husks, I get a LOT of nice, big berries. Last year, I picked quarts and quarts of berries off the same area that is now just withered husks. So very depressing!

Yeah, stress and overcrowding can cause that to happen, especially if there is less ground water or drying out/ inconsistent water during the winter/early spring. I try to keep it to 6-8 canes every 10-12 feet of producing vines with room at the bottom wire for next year's growth.

It did say that Cascades are good in zones 7-9, and I wouldn't be surprised if some areas had close to Zone 10 temps late winter/early spring. Maritime tends to be cooler because of the fog, so that may be why really coastal Cascade berries did better.

Cristo Balete wrote:Yeah, stress and overcrowding can cause that to happen, especially if there is less ground water or drying out/ inconsistent water during the winter/early spring. I try to keep it to 6-8 canes every 10-12 feet of producing vines with room at the bottom wire for next year's growth.

It did say that Cascades are good in zones 7-9, and I wouldn't be surprised if some areas had close to Zone 10 temps late winter/early spring. Maritime tends to be cooler because of the fog, so that may be why really coastal Cascade berries did better.

How do you keep the canes to a minimum? Mine spread quite happily, and I'm currently using that power to have them out-compete the salmonberry, Himilayan blackberrry and Evergreen blackberry that I don't want. Would it be enough to just cut the extra trailing blackberry at ground level? Won't they just grow right back up?

Also, do you know how much the berries need to be watered, or indications that they aren't getting enough water? Thank you!

It looks like Christine Lien of the "Garden Blessing" website mentioned earlier has an answer of how much to water the Cascade &/or Trailing blackberries:

I also mulch each bed with straw to keep the weeds down and the moisture from evaporating during the summer. During berry production I water after each picking, usually every three to five days. At other times during the spring and summer, I water once a week; more often if it has been extremely hot for a number of days.

She also fertilizes with chicken manure and all purpose fertilizer. My poor plants have only been watered once or twice this spring (aside from the little rain we've had), and I haven't fertilized them at all, figuring that since they were native to the area, they would be able to mange themselves. It looks like I was wrong and I need to pour more love into those poor blackberries!

Worth keeping in mind that even though the cascade berry is (perhaps) 3/4s cascading/trailing blackberry, it bears large berries, like a loganberry in size. This might impact how much water it requires...

Ours were always watered with the raspberries; once a week minimum, every couple days in the worst of the dry/hot times. They got some compost and a bit of manure yearly. With the same care, the raspberries did very well... until disease problems worsened after 20 years in the same spot.


For trailing blackberries, we had a bunch of those in the garden previously. They had bumbled along on their own for years just fine, but never produced much. I checked with my parents as to their fate, since I was mostly away; it seems that eventually they were treated to some water and helpful draping onto a wall, and produced many more berries for that year, but the following year apparently they yielded poorly, in part due to this dry-berry problem, and were then wiped out as they were considered a tripping hazard/morning-glory concealer...


The plant may be well able to survive without care, but that isn't any guarantee of useful yields for us. Just look at wild strawberries; good luck harvesting a few pints of those!


The tayberries which now occupy the old cascade-berry spot are full of ripe fruit now, and still not showing the problem in notable quantity so far; I've seen a couple berries with the issue, no more.

This spring has been incredibly dry in the PNW. Here in Seattle we got 1/4 of our normal May rainfall and it has yet to rain at all in June when we usually get over an inch of rain for the month. Normally I'd think you don't need to water natives much once they're established but I wouldn't be surprised if the weather has stopped the fruiting this year.

For what it's worth, tons of green healthy looking berries on the Himalayan vines in my neighborhood right now. I guess that's why they're so successful at being invasive!

How do you keep the canes to a minimum? Mine spread quite happily, and I'm currently using that power to have them out-compete the salmonberry, Himilayan blackberrry and Evergreen blackberry that I don't want. Would it be enough to just cut the extra trailing blackberry at ground level? Won't they just grow right back up?

Also, do you know how much the berries need to be watered, or indications that they aren't getting enough water? Thank you!

Nicole, Yes, clip extra canes at the base when it's clear there wont be any more, but not so low as to cut away at the "root ball". If there is a lot of rain this winter those might send out shoots, but are easy to clip.

I let 3 new canes go to the right, 3 new canes go to the left, bundle them on the bottom wire. Then after picking all berries, and cutting the old vines, I bring up the new growth, attaching 1 cane to Wire 1 (at the highest point), another cane to Wire 2 (a little lower) and Wire 3, etc. I choose 4 of the heartiest canes, clip out the weakest canes at the base, clip the tips so they will send out shoots to either side for next year's berries. The horizontal growth can happen in mild winter areas almost all winter long, so I keep them tied because of the winds, and windy storms. I only have 4 cross wires and a bottom wire to hold the next year's growth. You could have more cross wires if you wanted, but in drought years and high temps I haven't found the berries to be as productive.

I experimented with a very aggressive berry that I seriously want to get rid of, and I have to shovel the roots out over and over and over again. I also clip the unwanted "bad" vines as soon as I see them. If they can't get leaves, they can't feed the roots, but it takes really staying on them. I have tried spraying the unwanted vines with straight vinegar, with a kitchen bottle-type sprayer, but you have to do it repeatedly until it gives up.

I thought I would post an update on my blackberries, as I've had some--mild--success this year, as well as a few more observations. So, last year, there were areas where none of the flowers turned to berries (I've got at least 4 different patches that I manage the berries on--these areas are usually brush piles and stumps and mound that I encourage the berries to take over in). This winter, I applied a good 1-3 inches of duck bedding in those areas. Where the duck bedding was applied, 30-100% of the strands have made berries. I'm assuming the 30% is where I applied it less thickly than others (trying to apply it was difficult, as my berries grow up and over each other year after year). I also noticed that if an area of a blackberry cane didn't make berries and just "flower husks" the whole cane was no good.

All the areas were heavily watered with fishpoop water, but the only ones that really produced were those with duck bedding right over their crowns. I'm assuming they need more--or different--nutrients than are in the fishwater but are found in the duck bedding. I also noticed that the berry canes growing in new areas produced, but don't seem to the next year very well unless duck bedding is applied.

This year, I'm taking out the non-producing canes (I've noticed that by and large they are already dying), thinning out the skinny primocanes, and tipping the large primocanes. After the berries produce, I'll apply more duck bedding (I'd apply it now, but it's not aged, and I don't want to worry about "poop germs" splashing up on my berries).

Here's hoping that next year 100% of all my berry patches will produce!

Nicole, do you mean by "duck bedding" wood shavings? Do you know what kind of wood it is? Or just straw? Yes, aging is best for all wood products, plus nitrogen to get the carbon/nitrogen mix going.

My berries are doing really well, and there was normal rainfall which gave them more of an irrigation than a soaking, which may have released nutrients that had been caught up in the drought-ridden soil. I had been watering, but the plants always respond better when Mother Nature does it. I am going to treat my berries as heavy feeders and heap the compost/weed mulch/rotted manure around them a couple times of year. Of course the new growth is next year's berries, so I'll have to wait a year to reap the benefits of last winter's rain.

Definitely get the canes out of there that had berries last year, even if they have leaves and flowers, they are sucking energy away from the canes that will produce.

Cristo Balete wrote:Nicole, do you mean by "duck bedding" wood shavings? Do you know what kind of wood it is? Or just straw? Yes, aging is best for all wood products, plus nitrogen to get the carbon/nitrogen mix going.

My berries are doing really well, and there was normal rainfall which gave them more of an irrigation than a soaking, which may have released nutrients that had been caught up in the drought-ridden soil. I had been watering, but the plants always respond better when Mother Nature does it. I am going to treat my berries as heavy feeders and heap the compost/weed mulch/rotted manure around them a couple times of year. Of course the new growth is next year's berries, so I'll have to wait a year to reap the benefits of last winter's rain.

Definitely get the canes out of there that had berries last year, even if they have leaves and flowers, they are sucking energy away from the canes that will produce.

The "duck bedding" is pine shavings and duck poop. I usually just scoop out some bedding from their house, so it has some composted duck poop as well as fresh duck poop. I don't want to worry about listeria and ecoli splashing up on my berries from the fresh poo, so I only apply the bedding to my berries in the fall.

I've been trying to remove the old canes, but since my patches aren't trellised in any way, it's really hard to remove the old canes as the new ones have invariably grown over the "spent" canes. In the areas where they are tellised, I've been removing the old canes, but it's really hard on the mounds of blackberries. I don't really have the time to spend scarring my arms digging out old bramble and ruining the newer growth while I do it. So, for now in these cases, I'll just take out the small canes and give them all as much duck bedding as possible.

And, yeah, I agree, these blackberries do sure seem to be heavy feeders!

Wow, you've got your work cut out for you! I can see how in drought years that would need extra water since there's so much old stuff still trying.

I was just out chasing off a bluejay and a fat robin who were trying to steal the first of the blackberries!

I put pee (nitrogen) on wood and paper, soak it, and keeping it all damp makes it go faster.

Your grapes look good!

Nicole Alderman wrote:I've been trying to remove the old canes, but since my patches aren't trellised in any way, it's really hard to remove the old canes as the new ones have invariably grown over the "spent" canes. In the areas where they are trellised, I've been removing the old canes, but it's really hard on the mounds of blackberries. I don't really have the time to spend scarring my arms digging out old bramble and ruining the newer growth while I do it. So, for now in these cases, I'll just take out the small canes and give them all as much duck bedding as possible.

Have you considered a progressive, peacemeal approach? Taking a machete or clippers of some kind to one patch per winter, sacrificing its berries the following year to get it under control for the years to come, then moving on to the next patch the next winter?

Hi everyone, I'm new to this forum. When I was in the UK, I was inspired when I saw all the blackberry/bramble hedges that mark the perimeters of a farm. I thought it would be cool to do that in our chicken run and garden in the Netherlands. It would also be a source of free fruit for us and the chickens. I tried to do some research online as to how to train blackberry/brambles into a hedge or fence line. But they all require t shape post and wires, and this and that. But I don't see that with the English farms. A lot of my research suggests that they require work to go out and intricately weave them into the fence line. But I can't imagine the British farmers going out to their property every morning trying to weave their hedges. Does anyone have an idea on how I could do this? I am prepared to work, but not exactly how the online websites suggest to do it.

Roberta Wilkinson wrote:We've observed the same thing here.  Last spring we got really excited because there were tremendous numbers of flowers on the trailing blackberries at the bottom of the yard.  Come summertime though... nada.  Just like your pictures.

Some, elsewhere, do fruit, and they're delicious, hence the excitement.

They're dioeocious, and I think the "duds" are the flowers of male plants.  If you don't have to make fruit, you can put a lot of energy into flowers, hence the phenomenon of the most impressively flowered patches amounting to nothing.  They're important though, since you need them to pollinate your fruiting females.  I'm not sure of this, it's just the conclusion I came to and seems to make sense.

D Nikolls wrote:I can't tell for sure from the pictures, but it looks like the same problem we've observed on our cascade berries, which are a blackberry hybrid.

I do not think this is a case of a male plant, because the same vine would yield some successful berries. Am I correct that this is the same in your case, Nicole?

It does seem to be the whole plant that doesn't make flowers, and I did just read today (from Northwest Oregon Wetland Plants Project):

Trailing blackberry is a native perennial, low trailing shrub. Its trailing or climbing stem is armed with tiny, slender, hooked spines. This species produces male and female flowers borne on separate plants that are white or pink with elongated petals. Both flowers are five petaled. Trailing blackberry produces edible berries in open, sunny areas from April to August.

So, they do have different plants, and the males make no fruit!

What is weird is that there will be large areas of blackberries that don't make berries, where they made berries the year before.

This year was a good year for blackberries. I've been picking between a quart to a half-gallon every other day. I haven't picked that many since my first few years here. And I haven't done anything really different. Maybe the weather was better? Maybe more make plants died off and more female plants were growing? I just don't know!