Hi Marianne,

Thank you for reaching out to us at the UNH Extension Infoline.

Regarding your Clematis, it is not advised to split/divide specific varieties similar to how you may divide other perennials. They are extremely sensitive to division methods. Only specific varieties are recommended for division. For those varieties, you would cut the crown apart with a sharp knife or blade.

If you absolutely need to split/divide, they recommend layering versus tradition division for most varieties.

"Many clematis can be propagated by layering. Select 1 year old stems with good buds. Cut a 1-inch slit in the stem. Pin the stem to the soil in a container or on the ground with a wire. Cover the slit stem with soil and keep moist. Sever the stem when it has developed roots at the slit, gently dig up the rooted stem, and move it to the intended site." - UNL Extension
https://extension.unl.edu/statewide/douglas-sarpy/pdfs/ce/resources/ce-g1861-clematis.pdf

Additional Resources:
1. https://chemung.cce.cornell.edu/resources/dividing-perennials#:~:text=Clumping%20root%20systems%20are%20much,machete%20works%20well%20for%20this.
2. https://extension.unl.edu/statewide/douglas-sarpy/pdfs/ce/resources/ce-g1861-clematis.pdf
3. https://ask2.extension.org/kb/faq.php?id=150699
4. https://extension.umn.edu/planting-and-growing-guides/dividing-perennials  - spreadsheet: https://docs.google.com/spreadsheets/d/1Sv07afJ8jz9h_CGA_NNdjuFcaV83BUXtT2uIsYUsNdI/edit?pli=1&gid=<personal data hidden>#gid=<personal data hidden>
5. General Dividing Perennials Guide, UNH Extension: https://extension.unh.edu/blog/2021/03/when-should-i-divide-my-perennials#:~:text=Perennials%20can%20be%20divided%20in,to%20become%20established%20before%20winter.

I hope that this information is helpful! Good luck with your clematis! 

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