by George Buehler

There has been a flurry of activity on the ABSForum regarding the use of SuperThrive. The original question that was posted was whether the stuff really worked and if other root stimulator products were just as good.

One response was that every time she transplanted a bonsai, she soaked the roots in a SuperThrive solution for 20 minutes prior to putting it in a pot. Of course she believes it is the best thing since sliced bread.

Another response was that plants do not need vitamins however manufacture their own vitamins. Therefore how could the SuperThrive help the tree? This respondent said that he switched to a material called Roots 2 and found that this material worked very well.

A number of respondents reported that they had used SuperThrive in the past but gave up using it. Their conclusion was that they didn't see any benefit.

It appears that SuperThrive consists of Thiamine (aka Vitamin B1) 0.09% and 1-napthyl acetic acid (0.048%). Thiamine was promoted as a root stimulant in a Botanical gazette in the 1930's. The research report could not be repeated by other researchers, and the original authors retracted their reports since they could not repeat the results either. The 1-naphtyl acetic acid is a synthetic auxin (a plant hormone). Whether it works or not is questionable.

Other respondents said they replaced the SuperThrive with other materials like MicroMax, Sequestrine or Roots 2, and they got better results.

The directions on SuperThrive say that it is to be used with fertilizers. Could perhaps the combination of SuperThrive and fertilizer cause it to work?

I know from personal contact that the Montreal bonsai arboretum did use SuperThrive but abandoned its use a number of years ago because they could not see any positive effects with its use. They replaced the SuperThrive with MicroMax after they did a short study on that.

Apparently this controversy has been going on for years. I know several of our members use it regularly, and at least one swears by it. I also know it is extremely difficult to substantiate whether a particular chemical or process works or doesn't work especially since we are limited by the number of specimens we have. Also all research (or at least all of the research I have read) has been done on plants/trees in a greenhouse or field environment, not the bonsai environment (rock soil, small pots, constant trimming, and repeated root pruning). Therefore, my questions to the membership:

Who uses it? Do you use it in combination with other chemicals? Have you tried eliminating it or substituting it for other materials? How many trees did you do your experiment on? Please let me know. I will report the results back in a future report.