We love the alder tree, because it provides lots of great shade in the summer. So, when creating our yard renovation plan it was important to keep it. Because we were creating a large patio that wraps along the whole back side of the house, we then encountered the problem of having a huge tree growing out of the middle of the patio.
So we decided to create a planter box around the tree, set into the center of the patio. The closest thing that I can find online to what we were thinking for inspiration was this photo from 2 Pennies 2 Rub:
We wanted the tree box to perform a number of functions:
1. Keep the tree alive
2. Provide some additional seating on the patio
3. Add some color and texture to the patio with plants
One tall order.
I combed the internet for tutorials of people who had attempted something similar on their own and came up with zilch. Again, I think most people are smarter than trying to attempt a project this
We painted the dimensions on the ground (in pink above), making sure that there was enough clearance for a person to easily walk on the patio all the way around the planter box. The dimensions ended up rectangular, about 48" on the short sides and 52" on the longer sides. It was slightly bigger than we originally intended, because we were worried about hitting roots with the post digger... The last thing we want is a big redwood planter box in our patio with an hole in the middle because we killed the tree while building it.
We crossed our fingers that our plan was solid and got down to the business of digging the post holes.
There are no pictures of us actually digging the holes because the two man auger we rented took one man and one very reluctant woman to use (honestly people, it says two MAN right in the name, what did I get myself in to). We were able, however, to get four decent holes created at the four corners of the future box. Depending on the location of the tree roots, which we didn't want to disturb too much, we were able to get 18"-32" deep with the posts. Setting the posts into the ground will create the stability we need to hold the weight of the dirt in, and the weight of people sitting on the bench. We used pressure treated 4x4" lumber.
Once we set the posts in the holes, we filled the rest of the hole in with concrete for stability and support.
Here are the four posts in place around the tree with the concrete in place. The teepees at the bottom of each leg are yard stakes that we gunned in place temporarily to keep the stakes upright as the concrete was setting up.
These "base work" steps happened over the summer, before we were finished laying stone for the patio.
We actually got around to building and facing the box a couple months later, which you can see here - Part 2: Building and Siding the Box