Nothing.

In Feburary use nothing. If you were to repot during the growing season then you could use one of the above. I have used the Fertilome and I do not like it. It seems to have a tendency to burn my maples even when mixed less than full strength. I have been mixing superthrive, 1 capful per gallon with 1/2 strenght Fox Farm Big Bloom (0.01 - 0.3 - 0.7). You can also mix up your own transplant solutions that are more conentrated than Superthrive and wont' cost nearly as much. You would probably want to use a powdered rooting hormone or two, some diluted liquid 0-10-10 and whatever else comes to mind. Superthrive is a good product, but for the price it is hard to justify using enough of it. I still use it, but the 1drop methods they talk about are nowhere near acceptable for a transplant solution.

If I am repotting in the spring, I will do the above and then sometime around June I have added Root Blast only to up-potted liners and some small one gallons. I got a good deal on the product, otherwise I might try to duplicate the ingredient mix with less expensive products. What I liked about this product for newly transplanted plants is that it contains relatively low concentrations of ingredients that will decrease the risk of burn.
N 2%
P 1%
K 2%
(Nurtrients derived from Calcium nitrate, Super phosphate and Sulfate of Potash magnesia)

With the trace elements available from those sources I felt pretty good about using the product.

I know that was a little off your topic, but I feel there is some transition period from transplant to the time your trees are ready to handle "normal" fertilizers. The RootBlast seems like a good start as do some other liquid organics that offer nutirents in very low concentration.

I have not pulled the plants I tried this on last year, but that will happen this spring. Hopefully the results are good.

MJH

I was waiting with interest to see what type of responses appeared to this post, as I am very skeptical of any need for a "root stimulator" type of fertilizer with anything other than bare root material. Its so-called effectiveness just doesn't seem borne out by reality. And Superthrive (or Superjive as a witty horthead refers to it) has an amazingly effective advertising campaign as there is virtually nothing to it other than hype - active ingredients are barely .50% of the mix before dilution - and is generally considered to be pretty much snake oil.

IME, if you use a quality potting medium with a proper amount of compost and add a bit of slow release fertilizer (I prefer organic formulations), you will see an equal if not superior amount of healthy growth during the season than if you were to use a root stimulator type of product. And Superthrive is just making someone rich, not better or stronger plants and root systems.

GardenGal - I've shared this here at GW several times & on a couple of other forum sites as well. The title has been the same since I wrote it back in '98 or so. ;o)

Superthrive or Superjivesize>

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, youll find the manufacturerÂs 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 the product "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 summerÂs 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, IÂm 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 donÂt 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 Fassezke

Al, thanks for the informative post.

In the post you mention "bare-rooted repots", what does this mean? Do you bare root the plants at the time of repot?
I have always had this question of how much of the old soil to retain when repotting to a bigger container. It would be very helpful if you could spread some light on best practices for repotting.

thanks,
xman

Al, I knew you had written that piece - YOU are the witty horthead I was referring to :-)

GG - Now I'm embarrassed! ;o)

X - I bare-root/root-prune almost all deciduous material at the time of repotting. Acer tolerates this treatment very well, and the benefits are many. I'll start a thread soon about repotting/root pruning for those who are interested and willing to go through the extra work. You guys that are growing trees in containers are in a transitional zone between container culture and bonsai culture. You might as well at least know how the bonsai folks are able to keep their trees at a manageable size and healthy in smallish containers. Even if you choose not to use the info, you'll have a better understanding of what's going on with your trees & make better informed decisions down the road.

I'll be back later.

Al

Al thanks.

Looking forward to another of your great articles. I have learnt a lot from reading many of your posts(container soil mix, wicking, etc). In fact I wicked all my containers last week and was amazed at how much water wicked out even though I had watered these container about 4 days ago.
I am sure a repotting article would benefit a lot us especially the newbies quite a bit.

thanks,
xman

One study showed sunstantially decreased population of mychorrizae (important funghi for Acers) in the presence of high concentrations of phosphorus. One product actually combines the two in the same product.

One speculation was that the mychor are not as necessary when phosphorus is readily available, but it seems like mychor is good for more than that.

Nothing conclusive I believe, very preliminary, but interesting.

"Moreover, it has been
experimentally demonstrated that high levels of phosphorus are detrimental to mycorrhizal health and
lower the rate of mycorrhizal infection of root systems. This mutually beneficial relationship between the
fungus and the plant roots allows the plant to more effectively explore the soil environment and extract
needed nutrients. In the absence of mycorrhizae, the plant must expend more energy growing additional
roots and root hairs to accomplish the same task."

can I use root stimulator on my junipers and if so how many gallons at a time--thank you bill fisher