Topping is wrong for this unit

Scrolling through “share your grow” and I’m seeing many Grobo users having serious height issues similar to what I’m going through.
Topping encourages vigorous growth and I don’t believe this small machine can handle it. I also believe the recipes are 100% incorrect esp when topping. Topping should be used when there’s adequate space for your plant to grow, not a very small and tiny space like a Grobo. Yes I’m sure there are success stories using Grobo and topping no doubt but in general I don’t believe it’s a good idea. The developers at Grobo need to figure a way to adjust the recipe if you do top. The growth rate of a topped plant surpasses what the fixed recipe recommends which leads me to believe that’s why Grobo allows you to shift the growing schedule. The problem with that is that there are so many marijuana strains and getting topping advice from a grobo’er via the forum can and will be the wrong advice.

I was recently told (5 days ago) that my issue is “resolved” because a “champion” said my problem is not a problem because my plant’s height is starting to bud right at the second fan. Well, It’s now 5 inches above the second fan and not one white pistil is to be found yet. Now I have to do major work or I’ll have to scrap this whole project.

I suggest doing your homework, read, go to websites and gather as much info as you need before you do anything else your plant requires before coming in here looking for advice.


Hola @NYS,

Grobo has only been around for a few years so the overall experience with the machine is nothing compared to the overwhelming info out there on soil and other growing mediums. Most of the “Champions” here have a lot of Grobo experience but they are limited to the strains they have grown personally. They donate their time to help others and do it to the best of their ability. Not enough time to know all of the variables.

This product attracts nerds like me who like science and are attracted to the structure this machine offers or at least appears to offer. What geeks like me need to realize is that plants aren’t mathematical formulas and even when you do everything right, something can still go wrong. Many people can’t accept that. I have seen the same strain same exact genetics grow between 3 feet and ten feet, 8 colas to 60 colas. It’s genetics, environment, HST, LST, nutrients and more. I tell my friends that if you have a decisive black or white type personality you will struggle with growing because with growing you live in the gray.

I have topped my plants in the grobo and am happy with my nice even canopies. I do a lot of trimming and LST because I understand that I am growing in a very small box. I do not grow sativa strains because the sizing isn’t right for them and I don’t want to have to trim every day to keep her under control.

The more you learn, the easier it gets.


Every single grobo complaint since 2018 has been of the same thing.
Expectations & Assumptions

It really shines light on the differences in countries as we are trained consumers.

Of all the issues height is one of the easier ones to control, esp for photo periods.

This is why the forums are useful because someone likely has already failed or killed a plant the same way everyone else is.
This is the reason why everyone on the forums suggests growing unmodified grows for every strain you try prior to growing it for this exact reason @NYS stated. Each trim the plant will want to stretch, he is right. This is why many posts show to grow unmodified first… no one listens though. Even me. And look one extra week in late veg made my skunk outgrow the unit.