I'm no expert, but I do grow tomatoes and have a really short growing season so I need to know all the tricks to push plants to produce before first frost. For like hybrid determinate varieties, I only prune from the very bottom up on the main stalk when the plant is at least at 75% of its potential size and pushing out clusters of flowers, some with pea-sized fruit sets on them. At that point, I can tell who's taking up energy on the way to the fruit, and who needs to stay. Older looking, woody looking stocky branches growing off the main stem with only leaves and no new growth at the bottom of the plant go at that point. Also, if I'm seeing the season peaking and moving downhill towards fall which hits like a freight train here, I'll start pruning the small branches before the first cluster of flowers to direct energy to fruit production, but be careful not to clip off fruit producing branches. Determinate's (meaning they push out all their fruit at once, then die) only have one shot to make tomatoes, so a cut flower is a lost tomato. For like indeterminate heirlooms or something of that nature, I'll be more comfortable performing the same kind of pruning as mentioned above, because the plant will just keep growing until it gets too cold and it dies. However there are a few things to consider with indeterminate tomatoes (meaning they produce till frost comes. They'll just keep growing and growing) 1. If you clip off only from the bottom and remove suckers from the middle, it will grow up and likely get very tall. Think about supports. 2. If you clip from the top, it will grow out from the middle and get really wide and stocky. 3. Indeterminate tomatoes will keep pushing out flowers and babies for as long as you let them, potentially taking energy away from other developing fruit. It's up to you to take the chance, or clip new blossoms off. Some consider this nothing less than sacrilegious. I just say they're your plants, do what you want with them, especially if you start getting nervous as fall approaches. Remember that leaves are like (well they are) solar panels. The energy they collect gets distributed to the nearest parts of the plant on that stalk. So if there's a big healthy branch near a cluster of fruit, leave it so the fruit can collect the good stuff from the sun that branch is getting. Other reasons you should prune: Signs of disease like blight or any kind of fungus Branches that inhibit free air flow and promote fungus growth Branches that touch the soil should really be pruned off when the plant is a good size, but that's up to you. I can't think of anything else. I'm no expert, but I like answers that close the loop and don't leave loose ends.

January 2023. The Niwaki cloud pruning continues after I skipped last year somehow. What a difference six years of growth makes. A cloud pruning master I am not. I'm in no hurry to reach a final form and probably not brutal enough. I decided I wanted fluffier clouds. It is time to push the Fothergilla away from the Niwaki. They are getting crowded. That can wait until spring. I can dig a bunch of Fothergilla starts to plant elsewhere. I'm much better at herding cats.

Let's not get too nit-picky!! We are not talking about top pruning.....we are talking about the removal of a couple of extremely tall but almost leafless stems. The impact of their removal will have a negligible effect on the overall vitality and vigor of the plant. And it is also well established that pruning actually stimulates plant growth if done correctly and at the appropriate time, NOT resulting in "less of it than there would have been without the pruning."!! It's the OP's choice - leave or remove. But in all my years as a consulting horticulturist, I have never had the removal of strong, almost epicormic vertical growth be a detriment to overall plant growth and vigor.

the usual default.. is to prune after bloom ... if any ... i would probably sit on my patio.. with a few molsons or so.. and my pruning shears.. and artistically remove a few of the branches that start to piss me off as the beer take effect ... lol .. any that are rubbing on each other.. one or the other should go ... those would be the first ... then the down growing ones... but not too many at once ... i wouldnt remove more than 3 or 4 ... never forget.. you can always take more later.. you cant glue them back on ... i would insist someone take away the shears before the 3rd beer.. lol .. tree time is counted in decades .. and pruning is required within said decade .. there is no hurry ever ... unless its a 3 foot branch hanging over your house and you live in hurricane area .. and that aint z4 canada .. lol ken