# Brown streaks inside the stem when cut: likely causes and fixes

> Brown streaks inside the stem when cut on cannabis is most often Fusarium wilt or crown rot. How to tell them apart, the fix for each and what recovery looks like.

Also called: vascular browning, brown inside the stem, stem discoloured inside.

Run the checker with this sign: https://genetixbay.com/knowledge/diagnose/?at=stems&s=stem-internal-browning

## Likely causes, most likely first

### Fusarium wilt or crown rot (Possible)

- Kind: Disease; urgency: Act within a day or two
- Fix: No cure once infected: remove the plant with its medium in a bag, sanitise pots, trays and water lines, and use clean clones and new media. Reduce root stress (overwatering, heat, salts) on the rest.
- Recovery: No further wilting plants over the next 2-3 weeks.
- Confirm: Cut a wilting stem lengthwise: On a wilting or dying branch, scrape the lower stem and cut it lengthwise with a clean blade. Brown streaks in the water-conducting tissue point to vascular wilt (Fusarium). A dark, sunken crown points to crown rot. Disinfect the blade afterwards.
- Confirm: Send a sample to a plant diagnostic lab: For rots, wilts, leaf spots and viruses you can't separate by eye, send a fresh sample (whole plant with roots or a wilting branch with healthy and diseased tissue) in a sealed bag to a university or commercial plant diagnostic clinic. Results in days to 2 weeks.
- Confirm: Look at the roots: Hydro: lift the net pot and look at the root mass in good white light. Containers: tip the plant out with a hand over the medium and look at the edges and bottom of the root ball. Healthy roots are white to cream with fine fuzzy tips. Brown roots whose outer layer slides off between the fingers leave a bare thread: rot. Firm, evenly tan roots with white tips in coloured solution are staining.
- Article: [Fusarium in cannabis: wilt, crown rot and bud rot](https://genetixbay.com/knowledge/diseases/fusarium.md)

## Note

Guidance, not a guarantee. The checker weighs common causes against what you tell it; confirm with the tests before you treat, change one thing at a time and watch the new growth.