Florel, Pinscher, PGR on liquidambar and similar


New Member
I know there's been other discussions on this, I'm looking for more recent feedback.

I have not personally witnessed any measurable successes with PGR's and sweet gum. My PHC guy has several clients interested in the service, he wants to try selling it and asked my opinion. I do not sell or offer the service because most people are disappointed in the results and end up removing the trees anyway. I want to make sure that he, and more importantly his clients, have a reasonable expectation of success. My question to you; What success have you had and what would you contribute the success or failure to? What should his clients expect?


Active Member
Looking at the dose chart on the Cambistat label Sweetgum is a "A" rate, which tells me it is easily regulated. I use PGR's primarily for the secondary effects of drought tolerance because of the increase in root density and the thickening of the leaf cuticle for improved fungal resistance.

Something to certainly consider when using PGR's on Sweetgum should be the increase in flower leading to the increase in gumballs, which can make for a very unhappy client if they are not told of this from the get go.
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Active Member
I just realized you are looking for a deflowering agent and not specifically a PGR. I heard of mixed reviews of Florel. I used Snipper with some success but the timing is crucial to it being effective. You basically have a 7-10 day window to use it or it does not work. I have been hesitant to sell it in recent years because of inconsistent results that probably were because of poor timing.

Again, setting the expectation for the client is key.


Unfortunately, nothing new. The consensus seems to be that using deflowering agents on sweet gum works poorly, no matter if it’s a trunk injection (Snipper, Pincher), canopy spray (Florel), or trunk spray (Atrimmec). This includes talking to various chem vendors, who would like nothing more than to sell more of these products to us. The jury is still out on whether this is a matter of poor application timing or poor tree response, but I suspect it’s both. Believe me, if I thought there was even a 50% success rate, I’d present those odds to clients and try to sell treatments—clients really want a solution to their gum ball problems. Seems that the only solution is removal and replacement with a sterile Liquidamber.


Well-Known Member
I just realized you are looking for a deflowering agent and not specifically a PGR. ....
I think on a technicality, these are also regulating the growth of a plant. We normally think of PGRs as those that block gibberellic acid...but in a broad sense I think anything that is changing how a plant grows is a PGR???

On a side note: I simply refuse to tell a client I'm going to deflower their tree...


Well-Known Member
Hi folks, resurrecting this thread to ask about the ecological impact of applying this class of pgr to chinese tallow. Tallow seed is spread by water and birds, and germinated at higher frequency through bird poop, burial, and water. Does application of a seed killing pgr mean that one is doing one's ecological duty to combat tallow invasion, or does the dissemination of pollen (spread by insects and/or wind) to other trees nullify the intent of being an ecological steward?


Most well-known member
Good question. I have no idea.

Perhaps explore the chemical family a bit as well as diving into the SDS sheets for those products for better answers. They're residual components are likely toxic to something though.