Hello!

I bought a japanese maple in the fall of 2020 and planted it in my front yard to "replace" a blue colorado spruce that was dying and unyeildy. 8 cubic feet of earth around the maple's roots was replaced with good top soil mixed with some compost, with some mycorrhizae as per the botanist's advice. It was protected during the winter with some wind barriers to prevent freezing. It never grew and even seemed to become smaller since it was planted. I never dared to give it fertilizers to make sure I do not burn it.
Is there anything I am missing?

Here are some photos :

Where do you live? That will make a difference in growth rate.

The botanist gave you bad advice. Planting any tree in a hole of good soil and compost will slow growth as the tree is too comfy in the good soil to bother to grow out of the planting hole. That stunts growth.

Japanese Maples are notoriously slow growers anyway and that is the reason you should not fertilize.

Hello!

Thanks for the welcome!

I live in Montreal. Its zone 5 here.
We knew japanese maples are slow growers, but we still expected to have noticed *some* growth in one year at least.
That explains why japanese maples are so expensive when bought more mature...

JayZeke said:Hello ZeroShin
Lovely J.Maple!

I also acquired one last year and I am extremely surprised in how much it has grown …. (or hasn't! lol)
if anything I think my J.maple only grew about 4 leaves this year. but I also heard they were slow growers, just wasn't anticipating this slow

Don't forget, there are over 300 varieties of japanese maples and some do grow quicker then others. When planting in your garden, most important is that they require good drainage. The do not like wet feet. Fertilizing can distort their natural growth habit / cycle so I personally would not recommend any fertilizer. Regular watering during the hot summer months and once the roots establish you should be rewarded with a beautiful specimen.