Raspberries not flowering this year

Asked July 11, 2019, 12:44 AM EDT

I have grown 3 varieties of raspberries since 2014 Prelude, Caroline and Heritage. Each year they have produced well, and I have followed the guidelines for mulching, pruning and used organic berry fert each spring. They are lush and green and normal ht for this time of the season but did not flower! Even the ones I dug out and transplanted to other areas, or the ones that escaped the trellis have not flowered, so I am puzzled. Any thoughts here?
Thank you,
Elana BlueStone

Arvada, CO

Jefferson County Colorado

4 Responses

Thank you for your question. The flowering could be delayed due to our cool, wet spring, along with the two major freeze events. Let me ask a few questions to see if we can rule out other causes.

  1. Tell me about how you are watering: frequency, method, amount.
  2. Tell me about how you have fertilized....any change from past years that you indicated above?
  3. Any change in your pruning methods in the past year?
  4. You say they have good vegetative growth - does it look the same as in past years (eg, any stunting, deformity, color patterns)?
  5. Would you send me photos of the plants?
I look forward to hearing from you. Best regards,

Thank you Mari,
I took pictures of the rasp in the trellis and the ones I have transplanted along with the blackberry that is flowering and in berry now which I will include here.
I mulch them with leaf mulch that I compost from the leaves in the Fall, there is a drip irrigation system in there and I water about every 3 d unless it rains. So I try to pay attention and keep them moist but not wet. They are at the top of a hill so they have great drainage. I cut back the primocanes to the ground each year and tried to thin them out. I think part of the problem is that I need to thin more. I used a berry fert organic at beginning of spring and have my own compost I use along with the mulch. The veg growth looks exactly the same as other years very robust and green and full in there. I would like to send a few more pictures in a later email once you get this one. My blueberries are lovely although even there 2 of those plants seem to be "resting" this year....the strawberries, alpine variety are still producing very nicely. I just would like to know what to adjust...
Thanks for you expert input!

Dear Elana,
Mari asked me to do some additional research on your question. After looking at your answers to Mari's questions and checking them against CSU information sheets, it appears you are doing everything right. Patti, another volunteer clinician with extensive experience growing raspberries including Heritage confirmed that your plants should be flowering and setting fruit about now.

After researching viruses and possible environment effects, all I could come up with was the possibility of excess Nitrogen which can cause plants to produce lush vegetative growth but not flower or fruit. Mari and I would suggest a basic soils test and possibly a test of your compost and/ or a tissue sample. Here is
the link to the CSU Soil, Water and Plant Testing Laboratory
http://www.soiltestinglab.colostate.edu/documents/soilsample_horticulture.pdf .
Feel free to contact us if you have further questions
Warm regards,
Volunteer clinician

Hi to both of you,
Update here is that they are all now flowering. Late, but I am seeing them, even the June bearing Prelude is setting flowers. I guess we can chalk this up to the late spring, but I will get a soil test once this is all done as it will help determine if I have over fed them. My blackberry is full of fruit ripening now.
Thank you for your interest and help here. Pole beans are flowering now; cherry tomatoes are starting to ripen. I start them all from seeds in March.
Thanks again for your encouragement. Happy gardening!