How can I help little maples grow round?

[NS Gearhead]

Hi everyone! I'm new to the site. I've been searching for this info, but so far have come up empty.

I have 18 maples planted along my driveway. They've been there between one and four years. I replace the ones that die... last year I only lost one and I have 6 in pots waiting to go... but I'm thinking they're all established. They range from 6' to 8". One grew 18" last year! : )... until something ate it : (

I planted them 15 "steps" appart, and hope to some day have a nice tunnel effect.

My questions is; how do I make these trees grow to a nice round shape, as opposed to tall and skinny? I grew up on a christmas tree farm so I know the basics of pruning. I generally cut the lower brances as the tree gets taller, and make sure there's only one leader. (for now) I assume that once the lower brances are at the height I want that I can let the tops split and will form more of a round shape.

In do plan to hire an arborist once they get too big for me, but would like to guide them in the right direction in the meantime.

 

[stltreedr]

I've just started planting Maples along my driveway for the same effect. Some things to consider:

Trees that are grown in the open tend to spread further than forest trees. Trees in the forest are usually tall and skinny- trying to get to the light. If there are other trees around- make some room. In my case, I think this is the most important thing. You will eventually have to prune some lower branches on the driveway side to allow your vehicles to pass under.

You could, when the tree gets 20-30 feet tall, prune the top lead out of the tree periodically, this should release apical dominance to secondary branches and encourage growth in other areas. It will not be a one-time thing though. I do not plan to do this on my trees, as I want them to be as natural as possible.

Maybe a decade from now you will start thinking about choosing branches on each side of the drive that are somewhat symmetrical to start the lower level of your archway.

Bottom line, I don't think you will need to do very much to have a nice effect, just give it some time.

 

[NS Gearhead]

Ok, sounds good. They are pretty well in the open... that's why I planted them in the first place. The driveway is pretty bare compared to the rest of the property.

So what type of fertilizer, how much and when should I give it to them? From what I've read (and there's not much on maples), I think 10-10-10 slow release is what most say. Agree? Other then the potting soil that they were in when transplanted, they're in clay, on the edge of a slope. Any advice to help them grow is apreciated!

 

[stltreedr]

Most soils have enough of the nutrients required for native tree growth. Hard to give a specific fertilizer prescription without soil testing- but I would say a 10-10-10 slow release would be safe. I just sprinkle a few Tablespoons of Osmocote when planted and maybe a couple years after to promote growth.