Went for a run along the Chicago lakefront over lunch.
They just put in a TON of new landscaping S of McCormick Place - associated with a park to commemorate fallen firefighters. They must have planted over 100 sizeable deciduous trees in the 3-5" caliper range. Various species - I noted several locusts, oaks, and maples, tho tree and shrub ID is definitely not my strong point - especially when they are losing their leaves.
They also planted a good number (maybe 20+) really large specimens, at least 8-10" caliper. My question is about these larger trees. Each of these larger trees had 4 large J-bolts driven into the trunk, which were cabled to stakes. I wondered why this was done. I would have figured that it would be preferable NOT to screw large bolts into trees if it could be avoided.
The only thing I could figure was that when dealing with such large specimens, you had a relatively oversized crown compared to the recently transplanted root ball. As such, they might be more subject to being toppled by wind.
Of the smaller trees, only a very few were staked. There were a few that looked like cottonwoods - all of these were staked. And a couple of maples were staked. These were all done with saddles made of rubber tubing, instead of the J-bolts.
Staking is done to maintain stability for the rootball. On all trees that are planted the one thing you want to do is keep the rootball steady in order for the hair roots to grow out of the rootball into the adjacent soil to establish itself. Wind is one of the biggest natural challenges when it comes to establishing plant materials…especially if a tree still has its crown. Once a tree is blown back and the hair roots are ripped…well, it has to start over. Most of the time, the roots will regenerate…sometimes they don’t. If you have invested thousands of dollars in larger trees then it is best for one to invest in staking and guying.
As for the J hooks. This doesn’t really hurt a larger tree. After establishment they can simply leave them where they are since the tree will grow right around the wound and eventually over the hook if given enough time. Trees are incredibly tough…once they establish. On a younger tree, you really don’t want to even skin the soft bark. The cambium is typically very tender and may not be strong enough to overcome the damage. Never accept a tree that has been skinned up.
IMPORTANT: Be sure to remove the staking and especially the guy materials completely from the tree ONCE you know the tree is actively growing. I have noticed more and more that people are leaving the materials around their trees LONG after it’s neccessary. First off, this materials will choke a tree if left long enough. If you leave wires around a tree and the bark has grown around it…all you’ve done is sentenced this tree to die. The other reason you want to take off the materials as soon as you can is that even though the wind can be damaging to a transplanted tree during the establishment…it’s the wind that strengthens the trunk. This is what puts caliper on the trunk…wind resistence. In order for you tree to grow in girth, give it a chance to struggle against the wind without the staking and guying…only AFTER you know it’s established.