I also grow mostly dwarf conifers and JM's in containers and have been doing so for a long time. My typical routine is to dose with Osmocote Plus every spring (and when potting up new plants) and that offers a decent range of trace elements. I do hit them occasionally with Dyna Gro during the growing season as I use it on other containered plants but it is infrequent at best.

I also use a modified 5-1-1 soil mix as the watering requirement in summer for me with the gritty are just too onerous.

Be sure to add some calcium with Osmocote+. I'm not sure why, but they recently stopped adding calcium...They still add Magnesium though.

I switched to Miracle Grow Shake and Feed (12-4-8) CRF for that reason, and add a bit to the 5-1-1, but I mostly use DynaGrow Foliage Pro liquid though.

The phosphorus component of Osmocote Plus is supplied by calcium phosphate......so there IS Ca available in the mix :-) The need to add more may be more dependent on what you are growing. Most veggies, some fruits and conifers do have a sensitivity to a lack of adequate calcium.........JM's not so much. And I supplement with the Dyna Gro for the exact same reason.

Thanks for the comments gardengal and mblan. I think I'll mainly stick with the osmocote. Perhaps I'll pick up some dyna-gro, it seems popular here on gardenweb.

Are you sure GardenGal? I looked at their website and it claimed to provide 11 essential elements, Calcium was not listed, nor was calcium phosphate. Do you have a link to that info? Given my druthers, I'd rather use Osmocote Plus.

https://www.amleo.com/images/art/159125-label.pdf

If you look to the right of the guaranteed analysis, you will see the notation "derived from". That indicates calcium phosphate as a source of P. I can only assume that Ca is not available in a significant enough quantity to be include under the guaranteed analysis. But it IS there :-))

Interesting...The "Scotts" lists it, the "Osmocote" website does not.

http://www.plantersplace.com/osmocote-plant-food/outdoor-indoor-plus/