Blackberry (Marion Berry) Vines

Asked September 1, 2018, 5:15 PM EDT

My vines or stalks are getting so big and heavy with berries this summer. I had to tie them up because they were draping over my roses! Do you cut them down to maybe two feet tall in the fall? If so, will they produce next season? I am not sure how to take care of them. Can you give me some help, please?

Polk County Oregon

3 Responses

Hi and thanks for contacting Ask an Expert. Congratulations on your berry crop, it looks phenomenal. Marion berries are trailing canes. I am including a paper written by OSU on care, fertilizing and pruning. For the Marion berry, you want to leave the canes as long as possible, do not prune at all, not even the tips. After you harvest the berries, let the canes die back completely. They are giving the roots energy for the winter.
Marion berries can be damaged in very cold winters around 13 degrees F. Mulch around the plants in the fall. You can use any number of materials from straw to wood chips.
These berries produce two types of canes, primocanes which are new each year and produce berries in their second year and floricanes which will produce in the current year. The floricanes will die off at the end of each season. Unless you see a disease on the plants, do not remove the floricanes until they completely die back. The canes without berries or flowers should be trained onto a wire trellis (these are the primocanes).
Keep the weeds down as with most plants, they thrive WITHOUT the weeds. The document has detailed instructions on watering and fertilization. Please see the attached document for more info and pictures on trellising.
If you have further questions after reading the document, please contact us again. We are happy to discuss any questions you may have. Again, congrats on the berries, they look delicious.

Thank you very much, Sheryl, for this excellent article. It will help me take proper care of my blackberries! I appreciate the prompt response! I'm so glad I wrote in and didn't cut them back. This fall, I will build a better training ground like in the pictures.

Glad to be of help. One thought, make sure your trellis is strong, the vines tend to weigh down the trellis. I used steel poles with a guy wire staked in the ground then wire lines going across.