CannaTech The Vitamin B1 Myth

byDave Neal, Dr. Dyna-Gro



Plants manufacture vitamins and hormones used to regulate their growth.  In many instances, supplying these hormones, auxins and vitamins to plants can stimulate the growth of roots and foliage, regulate growth, internodal spacing and promote flowering.  While many of these occur naturally in plants, man-made versions which have the effect of naturally occurring plant hormones can the same effect as those naturally occurring hormones, auxins & vitamins.

You can find vitamin B-1 on the shelves in many garden centers.  Typical claims are that applying vitamin B-1 to new plantings helps to overcome transplant shock.  Is there any truth to this claim or is this merely another horticultural myth? 

Studies at the University of California, Davis conclude that there is no basis to support the claim that vitamin B-1 benefits plants by stimulating root growth or reducing transplant shock as many advertisements claim. 

Jeff Schalau, an extension agent with the Arizona Cooperative Extension, Yavapai County wrote: “Application of vitamin B-1 (thiamine) to root systems of whole plants does not stimulate root growth.  This myth arose from early work on plant growth regulators, called auxins, which were mixed with vitamin B-1. . . Various studies using both woody plants and annual flowers and crops failed to demonstrate that vitamin B-1 treatments provide any subsequent growth response.”

Robert Cox, Horticulture Agent, Colorado State University Cooperative Extension wrote:  “Several studies using (a variety of herbaceous and woody plants) have failed to demonstrate that vitamin B-1 treatments provide any type of growth response.  While root stimulator products are not necessary for transplant success, if you do use one, make sure it contains a rooting hormone and fertilizer rather than just vitamin B-1.  The vitamin B-1 is for marketing purposes rather than actual effect.”

An independent study to test the claim that vitamin B-1 applied to plants result in better foliage or root growth was conducted by the editors of Sunset Magazine, the results of which were published in the magazine.  Starting with fast growing bedding plants, six different treatments were used:

  • B-1 alone
  • B-1 with phosphorous
  • B-1 with 3-10-3 fertlizer
  • B-1 with 10-10-10 fertilizer
  • 10-10-10 fertilizer alone
  • Plain water

The results at two weeks showed new leaves and growth on all plants except those given vitamin B-1 alone.  The B-1 only plants showed no growth at all.  The plants in treatment 5 (fertilizer alone) were blooming after four weeks.  Those receiving B-1 with fertilizer (treatments 2, 3 & 4) took two more weeks to bloom.  After six weeks, fertilized plants had better color, more blooms and more foliage.  The shocking conclusion:  Plants that received only water out performed those receiving solutions treated with B-1!  Lesson: stick with water and nutrients.  Skip vitamin B-1.

Foods Rich in Vitamin B1

Foods Rich in Vitamin B1

As a result of in-house testing of vitamin B-1, Almaden Valley Nursery, a retail garden center, pulled vitamin B-1 products from their retail shelves, refusing to subject their customers to another snake oil product.  These studies should convince you that proper nutrition applications are the best bet for healthy plants.

What can you do to promote root growth?

For propagation of vegetative cuttings or promoting root growth when transplanting, there are effective options.  Both IBA (Indole-3-butyric acid) and NAA (1-Naphthalene acetic acid) are auxins that stimulate root growth. Some B-1 products contain one or both of these auxins which will be beneficial when transplanting.  One “Super …” product consists of NAA and B-1 despite claims of more vitamins and hormones than exist in nature.

NAA is particularly effective in inducing root growth on cuttings because its primary effect is to enhance lateral root growth rather than primary root growth.  However, NAA, like IBA suppresses top growth of plants and, therefore, should not be used on a continuing basis.  One or two applications after transplanting rooted cuttings or other plants into new containers or the ground will suffice to promote lateral root growth.  The plant can take over from there with its naturally generated hormones and auxins. For optimum results, insure that your plants are receiving complete nutrition*, adequate water and proper levels of light.

Dyna-Gro KLN Concentrate and Root-Gel® contain both IBA and NAAand are very effective for vegetative propagation and stimulating root growth at any time. KLN Concentrate is most effective on herbaceous cuttings in general while Root-Gel® is often more effective for more difficult to root, woody cuttings. In addition, Dyna-Gro Pro-TeKt®: The Silicon Solution® has produced 100% success rate in rooting vegetative cuttings without the application of any auxins or hormones.  Combined with KLN Concentrate, the two are even more effective used as a drench into the rooting medium before or after sticking the cuttings.

Dr. Dyna-Gro

*Seven macro nutrients: nitrogen, potassium, silicon, calcium, phosphorus, magnesium and sulfur plus ten trace elements: iron, copper, zinc, manganese, boron, cobalt, molybdenum, chlorine, sodium and nickel.

Dr. Dyna-Gro*,

* If you have questions about this article contact Dave Neal, Chairrman and CEO of Dyna-Gro Nutrition Solutions at 800-Dyna-Gro or email him at  Dave Neal started Dyna-Gro in 1984. Dave holds a BA in Political Science with minors in Mathematics and History, a MBA in Finance and Accounting as well as a JD degree in law. For over 35 years he has been a member of Mensa and the American Association for the Advancement of Science.