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Not all are much enamored of Superthrive, and it DOES contain ingredients that WILL hurt your plants if overused. It contains synthetic auxin, the same growth regulator that was used in defoliants in Viet Nam. This question arises soo often, that I saved a synopsis of an experiment I've repeated 4 times, with some loose controls in place. You may, or may not find it interesting, but I am pretty settled with my conclusion(s).
Superthrive or Super-Jive
The question of the value of Superthrive as a miracle tonic for plants is often bandied about in horticultural circles. Several years ago, after reading claims that range from "I put it on and my plant, which had never bloomed, was in full bloom the next day" to "It was dead - I put Superthrive on it and the next day it was alive and beautiful, growing better than it ever had before", I decided to find out for myself. If you look for information on the net, you’ll find the manufacturer’s claims and anecdotal observations, totally lacking in anything that resembles anything like a control. Though my experiments were far from scientific, I tried to keep some loose controls in place so that I could make a fair judgment of its value, based my own observations. Here is what I did, what I found, and the conclusions I made about my use of Superthrive.
On four separate occasions, I took multiple cuttings from the same plant. The plant materials I used were: Ficus benjamina, (a tropical weeping fig) Luna apiculata (Peruvian myrtle), Chaenorrhinum minus (a dwarf snapdragon), and an unknown variety of Coleus. In each instance, I prepared cuttings from the same plant and inserted them in a very fast, sterile soil. Half of the cuttings were soaked in a Superthrive solution of approximately 1/2 tsp per gallon of water. The other half of the cuttings were watered in with water. In subsequent waterings, I would water the "Superthrive batch" of cuttings with a solution of 10 drops per gallon and the others with water. The same fertilizer regimen was followed on both groups of cuttings. In all four instances, the cuttings that I used Superthrive on rooted first. For this reason, it follows that they would naturally exhibit better development, though I could see no difference in vitality, once rooted. I can also say that a slightly higher percentage f cuttings rooted that were treated to the Superthrive treatment. I suspect that is directly related to the effects of the auxin in Superthrive hastening root initiation before potential vascular connections were destroyed by rot causing organisms.
In particular, something I looked for because of my affinity for compact branching in plants was branch (stem) extension. Though the cuttings treated with Superthrive rooted sooner, they exhibited the same amount of branch extension. In other words, internode length was approximately equal.
As a second part to each of my "experiments", I divided the group of cuttings that had not been treated with Superthrive into two groups. One of the groups remained on the water only program, while the other group was treated to a 10 drop per gallon solution of Superthrive. Again, the fertilizer regimen was the same for both groups. By summer’s end, I could detect no difference in bio-mass or vitality between the two groups of plants.
Since I replicated the above in four different trials, using four different plant materials, I’m confident in drawing some conclusions as they apply to me and my growing habits or abilities. First, based on my observations, I have concluded that Superthrive holds value for me as a rooting aid, or stimulant if you prefer. I regularly soak the soil, usually overnight, of my newly root-pruned and usually bare-rooted repots in a solution of 1/2 tsp Superthrive per gallon of water. Second, and also based on my observations, I don’t bother with its use at any time other than at repotting. No evidence was accumulated through the 4 trials to convince me that Superthrive was of any value as a "tonic" for plants with roots that were beyond the initiation or recovery stage.
The first ingredient listed as beneficial on the Superthrive label is vitamin B-1 (or thiamine). Growing plants are able to synthesize their own vitamin B-1 as do many of the fungi and bacteria having relationships with plant roots, so it's extremely doubtful that vitamin B-1 could be deficient in soils or that a growing plant could exhibit a vitamin B-1 deficiency.
Some will note that I used more of the product than suggested on the container. I wanted to see if any unwanted effects surfaced as well as trying to be sure there was ample opportunity for clear delineation between the groups. I suspect that if a more dilute solution was used, the difference between groups would have been less clear.
It might be worth noting that since the product contains the growth regulator (hormone) auxin, its overuse can cause defoliation, at least in dicots. The broad-leaf weed killer Weed-B-Gone and the infamous Agent Orange, a defoliant that saw widespread use in Viet Nam, are little more than synthetic auxin.
Al F.
