One of the fun things about writing this gardening blog is that sometimes one article leads us to another topic we want to explore. Last week we wrote about transplant shock, how it affects seedlings and plants, and then how we can prevent or mitigate it in our own gardens. We got some followup questions from readers about the subject, many of which were variations on “Does adding B vitamins to the water or the soil help prevent transplant shock/promote new root growth?” We had never heard this particular advice, so in grand Gardzen fashion we decided to dig in and see what we could learn. What we found was a series of long-standing gardening myths and misconceptions, so we’ll share our results with you here today.
Gardzen Executive Summary:
· The idea that adding B vitamins, especially B1 and B12, to either water or soil helps plants to avoid transplant shock or grow new roots has been around for a long while.
· As far as we can tell, there’s no truth to this gardening myth; every piece of research we can find says there’s no connection between adding B vitamins and new root growth or preventing transplant shock.
· As we discussed in our article on transplant shock, the best way to prevent it is by watering deeply and regularly after transplanting.
· We’re not scientists, we’re gardeners, and the research is ongoing. However, for now, we can dismiss adding B vitamins to transplanted plants or seedlings as a gardening myth.
Vitamins B1 and B12, Transplants and Root Growth
The idea that vitamins B1 and B12, either together or separately, are good for either transplanted plants or root growth goes back a long way. The first reference we can find comes from the 1930s, when two researchers named James Bonner and Jesse Greene published a paper demonstrating that significant quantities of B1 were found in the new root growth of pea plants whose leaves developed in the light and that lower quantities of B1 were found in peas plants whose leaves developed in the dark. The article’s conclusion states that “Organic manure contains appreciable amounts of vitamin B1. The beneficial effects of manure upon plant development may be owing in part to its content of vitamin B1. The vitamin B1 content of soils may be expected to be derived also from plant debris and from soil microflora.” We’re not in a position to assess the validity of this research, but we can point out that this is a long way from proving or suggesting that adding B1 or B12 as fertilizer helps root growth or prevents transplant shock.
However, this article may have been the spark point for a host of commercial fertilizers, soil amendments, and plant growth supplements extolling the virtues of B vitamins for plant growth. While it is true that healthy soil biomes and healthy plants contain B vitamins, the reality is that this is a product of health not a cause of it. The commercial products containing B vitamins for root development were just marketing; while they likely didn’t hurt plants the B vitamin content didn’t help anywhere near as much as advertised.
This conclusion shows in contemporary research, which demonstrates time and again that added B vitamins aren’t especially helpful for preventing transplant shock, promoting new root development, or otherwise improving plant health. To quote Dr. Linda Chalker-Scott of Washington State University’s Extension Center: “ Applying vitamin B-1, or thiamine, to root systems of whole plants does not stimulate root growth. This is a myth that refuses to die, though it has been repeatedly refuted in the scientific literature.” We are hard pressed to put it any more clearly than that. Dr Chalker-Scott goes on to conclude that a good nitrogen fertilizer and good soil moisture are the best support for new plants, and that they’ll produce the needed vitamins on their own if they’re kept healthy. We’re relieved to hear that we got it right, according to a well-respected researcher and scientist, and that our previous article is a good guide for preventing and mitigating transplant shock!
So, in conclusion: put the vitamin supplements away, give your transplants and seedlings plenty of water and fertile soil or well-balanced fertilizer, and let this gardening myth pass into history.
Gardening Myths, Legends, and Traditions
Let’s be honest for a moment: we all have some gardening lore that we believe even though it’s not backed by the research. Here at the Gardzen Test Gardens in southeastern North Carolina, USA, we still do some planting by the signs and we often start gardening season on Good Friday, as these are traditions local to us and they help keep us connected to our gardening heritage. There’s nothing wrong with traditions as long as they don’t cause harm to our plants, ourselves, or the environment and as long as they don’t lead to us wasting money.
We’d love to hear about your favorite pieces of gardening lore, scientifically validated or not. Let us know in the comments or via email—Gardzen is all about community and we always love to hear from you!
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