What's new

Topping = longer to show sex?

ISM2

Member
Does topping a plant in veg lengthen the time it takes for that plant to show sex while in veg?
 

sprinkl

Member
Good question, but I think it's possible, it's the primary suspect as to why my first outdoor never started flowering because I kept topping, almost weekly. I do think there were preflowers. Being a complete noob first grow it could have been a few other reasons too.
I think the plant experiences some shock with every injury halting growth for a short while. Also the energy it put into the plant part you cut off is lost, and less photosynthesis capacity so slower growth(of the roots) compared to non-cut plants. On the other hand maybe preflowers have less to do with the amount of growth than the age or amount of dark cycles. But then what with plants on 24/0 light?
 

The English Cut

Well-known member
In my experience it totally depends on the plant. I routinely top all my plants at the 4th or 5th internode during veg, some strains react better than others, but even with individuals of the same strain I've seen a huge difference in how long it takes to show sex, for example I have 3 plants of the same strain about 3 months old, one showed sex over a month ago while the other 2 still haven't decided yet.

But yeah, what sprinkl said is spot on, any pruning/damage will definitely slow the plant down. There's things you can do to minimise the shock like topping at the right time in the lunar cycle, I also spray with aloe vera or comfrey after topping which seems to heal the damage faster.

I've also noticed that plants recover much quicker from a simple apical pinch than from the FIM style of topping.
 

iTarzan

Well-known member
In my experience topping delays preflowering.

Induce branching by LST. This won't delay the appearance of preflowers.
 

ChaosCatalunya

5.2 club is now 8.1 club...
There are times when one HAS TO top because of stretch...

No, never, unless you want to slow a particular plant down, just train her over. When you chop the top off a plant you loose the Auxin from the apical meristem, the top tip, so the plant must remanufacture these, setting her back 1 to 2 weeks, all depending on variety as the English cut says.
 

The English Cut

Well-known member
No, never, unless you want to slow a particular plant down, just train her over. When you chop the top off a plant you loose the Auxin from the apical meristem, the top tip, so the plant must remanufacture these, setting her back 1 to 2 weeks, all depending on variety as the English cut says.

Science. Very interesting, I may have to stop pinching out so early. Really I only do it because of the need to maximise bud sites and reduce the chance of mould so I could start later on or simply LST and stop pinching altogether.

Does the same thing count for clones and fully grown plants or just seedlings? I mean how much does repèated pinching out slow down growth or even flowering?

If it's a question of auxins, then might an application of seed sprout tea help remedy the situation? It's packed full of auxins but I've no idea if specific auxins need to be produced by the plant itself or if it can take them up via the roots. I'm going to start some now and see if it helps, I've got some clones I've just topped to test it out on.
 

Betterhaff

Well-known member
Actually when you top you eliminate the auxins that are produced by the apical meristem that prevent lateral growth from the node meristems below. The delay comes from growth now occurring at these sites, it’s not actually a delay, it’s just now the sites closest to the topped portion are now the new apical meristems and will start to produce higher concentrations of those same auxins.

Because of this new growth the onset of preflowers may be delayed because the plant is concentrating more on generating growth from these new sites.

A plant won’t show preflowers until it is sexually mature regardless and some take a change in light cycle to show any sex. I’ve rarely seen a plant show preflowers before they reached the 6 or 7 node level.
 
Top