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Raspberries #840316

Asked July 12, 2023, 2:43 PM EDT

We have 17 rows about 40ft long that we planted about 10 years ago. Progressively each year we are getting more and more of this dead and browning in our raspberries. We manually water the raspberry bushes. Last fall we notice a elongated purple more on the new canes. Could be please advice what is wrong with our raspberries and what we can do to prevent us from loosing them.

Charlevoix County Michigan

Expert Response

Hi Margaret, thanks for the question.  

Sources that raspberry planting at ten years is getting near the end of its productive cycle. It may be possible to rejuvenate if the problems can be resolved.  Detailed pictures of the areas between the good and bad can help. Pictures of the plantings would also be a benefit.  Some detail as to spraying, pruning, irrigation, etc. may be helpful., Also, could provide some info on the "elongated purple" statement? check out the following links:

Controlling raspberry cane borers - MSU Extension

Raspberries: Primocane tips are wilting | Berry Diagnostic Tool (cornell.edu)

Raspberry cane diseases | UMN Extension

I look forward to your response.

An Ask Extension Expert Replied July 14, 2023, 9:23 AM EDT

Hello! Let me start by saying these raspberries have been improperly maintained for most of the 10 years of their lives & their problems started about 3 years ago. We've discovered that ignoring them is not the answer.


picture #1 the good end of the berry patch . The rows are 5' apart the the baby plants were planted 2' part. We have always had to water with a sprinkler, Fertilize once a year in the spring & have cut out the old canes in the fall. For several years we weren't too good about cutting back the canes but have now figured that out - probably still a bit timid with the clippers.

picture #2 the bad end, where we first noticed this issue. The first bush in that row actually looks pretty good, it is a Latham and the other sickly ones are Noves. There are wild raspberries all around this berry patch - as close as 50 feet- and they also seem to have the same problem. I read the articles you sent to me & I wouldn't be surprised if we have one, two or all 3 of those fungi.

picture #3 is one of the few rows that doesn't look too bad. They all looked like this a few years ago. The only spray we use is Bonide "Capt.Jack" organic pest spray to keep the japanese beetles at bay.

picture #4 sample of the first row that got sickly first. We didn't do any weeding this year because we knew we had to take measured to fix our errors.

picture #5 sample of second row that soon followed suit.

As for the purple spots, my husband says he sees them on the new canes when he prunes in the fall. No picture available.
If you can identify our problem we will promise to follow your advice for repairing and will take better care of the berries in the future. Thanks for your time and expertise.

The Question Asker Replied July 17, 2023, 3:47 PM EDT

additional pictures

The Question Asker Replied July 17, 2023, 3:47 PM EDT

Hi Margaret,

Looking at the patch you are probably right about the multiple fungal infections.  The purple spot could be spur blight. Be sure to get rid of nearby weeds and any wild brambles if possible. Overhead watering can spread disease and prolonged leaf wetness can create an ideal environment for diseases. Consider drip irrigation.   Be sure to water properly, one inch a week, make sure you have good drainage. Check how much water you are actually putting down. Sanitize tools between plants so as not to spread the diseases. Mowing down the patch may be a good way to solve the problems as stated in the UMN link may be the place to start but with summer bearing raspberries you wouldn't have berries next season. Treat diseases with one of the fungicides suggested to reduce the spread.  Remove all the infected material and burn or bag.

I hope this is helpful.

An Ask Extension Expert Replied July 18, 2023, 10:27 PM EDT

We had spoke about an  elongated purple spot more on the new canes.  I have attached picture of these spots.

The Question Asker Replied August 07, 2023, 3:50 PM EDT

Hi Margaret, 

This is probably spur blight but could be cane botrytis. Both are fungal.  Take a look at the following links for more detail and control information.

Raspberry cane diseases | UMN Extension

Ontario CropIPM (gov.on.ca) - spur blight

Spur Blight of Red Raspberries | Ohioline (osu.edu)

Ontario CropIPM (gov.on.ca) - cane blight

An Ask Extension Expert Replied August 07, 2023, 8:47 PM EDT

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