That's a quick solution that works. Alternatively, if you have time, you can do as they did when creating the New York Botanical Gardens: truck in and spread huge amounts of organic matter for a period of 10-15 years until your heavy clay morphs into a perfect humus rich growing medium. Gomero
Sounds pathenogenic. Awhile back I lost a bigleaf magnolia to what appeared to be Armillaria. It had taken many years to start becoming a fairly substantial specimen - with a long ways to go before it had reached the 50' height displayed by other examples in this area. But it had been flowering for at least a few years. And was a surprising number of years old when I first bought it.
I have an apology to offer to a certain someone. It is unfair for someone to come out of the woodwork after a long period of time (almost five months) of inactivity in this forum and wreak his ugly head by stating an exception to a well intentioned post. I am sorry for this and the trouble it may have caused. I've been subjected to worse in this forum. Doesn't anyone use the keyword search feature and go back in time to read if anyone else has broached a similar subject in the past? I do not amend potting soil or planting soil with fertilizers, any recognized form at planting. I have in the past used topical applied liquid forms of fertilizers on Citrus and Fruit and Nut trees at planting but never applied to the bottom of the hole and then backfilled with soil. I've seen what just a little bit of commercial granulated fertilizer can do to a root system placed at or near the roots at planting. Lift the tree out of the ground a couple of weeks later and take a look at the root damage. I've seen what too much elemental Sulfur can do to a potted, containerized, Camellia and that is pretty much choke off the roots from being able to breathe oxygen when used as a top dress. [We go in with the right idea to lower the soil pH but there is no one to tell us how much is too much or how little is too little.] We have to play it by ear and we have to learn the hard way which is acceptable for a specific plant for us where we are and from a plant loss or two learn what is not to our benefit. Some people that have been around plants for a long while like Ron has side with caution for good reason. Ron posted a link to the Whitcomb books. The 'Plant Production in Containers' book is well worth having and is still one of the better books ever published for container growing. A used book can be found from an online source right now for a lot less than what we paid for our hardback copy years ago. What are you waiting for? I cannot speak for the Tree-tone as I have never used it. In theory it may be a good product to use on ornamental plants as a topically applied (applied on the surface) side dress. I cannot vouch for it otherwise until we have better and broader spectrum information as to how well it works on Maples. Jim