How to Re-Veg a Cannabis Plant (and Why You Might Need To)

A step-by-step guide to bringing a flowering plant back into veg so you can save the cut.

By Colin Gordon & Ben Owens

Sometimes a cut is too good to let go but the backup clones didn’t root, or you didn’t take any to begin with. Maybe you’re running a pheno hunt and don’t have the space or certainty to keep mothers for every contender.

That’s when re-vegging becomes a valuable tool.

It’s not ideal, and it’s not always successful, but when it works, it gives you a clean path to recover a keeper.

This guide walks through how we successfully re-vegged Rocket Queen and All The Sauces (The Wrank × Zkittlez) to preserve them post-harvest, plus the exact conditions and lessons learned along the way.

How to Re-Veg a Flowering Cannabis Plant

Step 1: Start Before You Chop

If you know you’re going to re-veg, don’t wait until harvest.

Switch your lighting to 18/6 for 5–7 days before chop to begin triggering the hormonal shift out of bloom. At ETHOS, we will flip the lights on day 64 of flower (in a room scheduled to go to 70), letting the plants start to decelerate from flower while still finishing. No negative impacts were observed on either flower quality or resin.

Note: Don’t increase light intensity during this phase. You want to decrease intensity when increasing duration.

We actually reduce total DLI during this transition by turning off ⅓ of the lights.

You’re not trying to push the plant, just signal it to shift.

Step 2: Chop Smart & Leave Enough

When harvesting the plant, leave at least 4–8 healthy branches with multiple growth nodes on each. Try to keep the whole plant under two feet tall when possible.

Avoid stripping the plant completely. You want a stable base of semi-mature tissue that can regrow without being shocked or stressed. Weak or brittle growth won’t reboot well.

Multiple growth sites increase chances of a successful reveg.

Step 3: Lower Light Intensity & Adjust Environment

After chop, keep the plant under 18/6 lighting with lower intensity (~500 µmol max).

Don’t blast the plant. You’re not vegging yet, you’re waiting for a response. During this “dormant stall,” new growth may not appear for 2–3 weeks.

Environmental targets:

Temp: 82-88°F daytime is ideal. 68+°F at night.
Humidity: Keep things steady (50-65%is optimum range); avoid swings.
Substrate: Moist but not saturated. These plants won’t be drinking heavily, and overwatering invites problems.

Step 4: Don’t Overfeed, But Don’t Starve

The root zone doesn’t need much, but it does need something.

We use a light early veg mix with available nitrogen and phosphorus to signal metabolic activity. The rhizosphere is typically depleted at this point, and full-strength feeds aren’t necessary.

Microbial teas can be helpful to fight any pathogens that may be lurking in the rhizosphere while supporting roots during the re-veg.

Water lightly. Splash the surface daily to maintain moisture without oversaturating.

Step 5: Watch for New Growth, Then Prune & Clone

Once you see two or more healthy re-growth sites, remove the rest of the old branches.

This focuses the plant’s energy and allows the active sites to build momentum.

As soon as those sites produce a healthy, viable clone, take your cuts.

Don’t try to re-mother. The plant is in a fragile, transitional state, and its immune system is compromised. Prolonging re-veg increases susceptibility to pest and pathogen issues.

Not every cut will re-veg at the same pace.

In our facility, I was revegging several Rocket Queens. I had viable clones within 2 weeks off of the first one. And it took up to 4 weeks for the last one. Everything was the same. Results can vary. Expect a window, not a guarantee.

Tips & Troubleshooting

Start Early: Earlier transitions = better success. If possible, begin light flip before harvest (5-7 Days).
Avoid Cold Temps: Colder root zones slow the re-veg process and make the plant more vulnerable to mold, rot, and pathogens.
Use GA₃ if Needed: If you have a weak-rooting plant or an extremely fast-flowering, dense plant, a small dose of gibberellic acid (GA₃) can help trigger growth. We’ve used 5ml pre-mixed bottles sourced online. Not usually necessary, but helpful for stubborn phenos.
Plan for A Re-Veg to Take Time: 3-4 weeks is typical in optimal conditions.

If you have the space and you are able to clone the plants before you flower, that is preferred. If you can avoid a re-veg as Plan A, do so.

When executed with care, it’s an effective method for saving keeper cuts you didn’t back up or weren’t ready to commit to.