The story goes, as told in Tree City USA Bulletin #4, that two families moved into their new homes on the same day. They both celebrated their new home by planting a young shade tree to commemorate the celebration. One family planted their tree, watered it when they were supposed to, but otherwise left it alone to let it get on with its growing. The second family planted their tree, watered it when needed, and every year they spent a little bit of time inspecting and pruning their tree.
Fifteen years down the road, the first family’s shade tree looks a bit messy, is shorter than expected, and is starting to become a hazard. Two leaders at the top mean the crown is weak and at risk of splitting. A broken branch has allowed water and decay to start building in the trunk of the tree. Branches that have been allowed to rub together have also ushered in decay and pests. Since the untamed crown is full of branches going every which way and packed densely with leaves, the tree catches the worst of the wind and is liable to break in a storm. It’s also a hazard for passersby because low-hanging branches are at head height. Suckers around the bottom of the tree have grown up and crowded the tree, while also sapping its energy. This poor tree is very unattractive, and more of a liability than an asset. Trying to make this tree safer is going to be very expensive, and may not be possible. The tree may even need to be removed.
The second family’s shade tree is tall, strong, and healthy, thanks to their dedicated pruning. Its canopy is lush but open enough that wind flows through without damaging the tree. This tree has withstood several big storms in the neighborhood that other trees did not survive. It has a balanced and pleasing shape and no dead wood. Its central leader is strong and sturdy, and its branches are equally healthy. This tree is not a safety risk, and when the home goes up for sale, the realtor says that the beautiful shade tree was selling point for the new buyers.
The moral of the story is that a little preventative pruning and shaping, while your new tree is young, sets the tone for the rest of its life. Proper pruning helps trees grow strong and resilient, and will likely prevent expensive calls to an arborist in ten to fifteen years.
Here are a few tips for pruning shade trees in the Quad Cities Metropolitan area.
Tips for Pruning Young Trees
So, you just planted a brand new deciduous shade tree in your yard, and you want to prune it correctly to make sure it grows well and stays healthy. For the first year, you can leave it alone and avoid pruning unless you need to remove dead or damaged branches. Young trees lose quite a bit of their root system when they’re uprooted for selling. That first year is critical for them to focus on recovering and expanding their root system.
Once your shade tree has been around for about a year, you can start doing a little pruning. There is one fundamental guideline to remember; don’t remove more than 25% of a tree’s living branches per year.
In the first year, you’ll want to identify the best candidate for being a strong central leader for your tree. When you’ve identified the most likely candidate, check to see if it is competing with any other branches for that vertical center trunk. Remove any competing branches.
Have a look at the angles of the branches sticking out from the tree. The ideal angle is about 60º or aiming for 10 o’clock or 2 o’clock. If branches are growing at very tight angles, or very wide angles pointing down, remove them.
Check for the spacing of branches. If two larger branches are growing close together, remove one. Similar to the strong central leader, it’s a good idea to identify and encourage strong lateral branches. Prune away competing branches.
Prune any branches angled towards the main trunk and any that are crossing other branches or sticking out at odd angles.
Remove any suckers, shoots sprouting up from the base of the tree, or straight up on branches. These only take away energy from the main tree. Cut them off as soon as you see them.
Once your tree is a few years old, you’ll want to start thinning it a bit. Step back and have a look at the overall shape of your tree. Keep that in mind while pruning. Lateral limbs should be spaced 8-12 inches apart when a tree is young. Remove all small branches from limbs that angle straight up or towards the center of the tree.
If your tree is anywhere near a structure, like a house, fence, or power line, look for limbs that may interfere with the structure when they’re fully-grown and remove them.
Once your tree is three to four years old, you can slowly start pruning off lower branches to raise the bottom of the tree’s crown. Do this slowly, only removing a few lower branches per year. Keep in mind that branches do not move up as the tree grows. A branch that is five feet above the ground when the tree is four years old will still be five feet above the ground when the tree turns twenty.
Generally, pruning shade trees should be done in the middle of winter, when trees are dormant. Winter pruning encourages vigorous new growth, and summer pruning will slow the growth of pruned limbs down. There are a few exceptions, though. Trees that flower in the summer or fall on that year’s new growth should be pruned in winter. Trees that flower in spring on old growth should be pruned as soon as they finish flowering. In general, avoid pruning in fall; wounds are slower to heal, and there is a higher risk of infection and pest infestation. You should remove dead or damaged limbs as soon as you find them, regardless of the season.
Every year, inspect your tree for dead wood, damaged limbs, and disease. Check for branches that rub against each other, and check the overall shape of your tree for any irregularities. By the time your shade tree is six to eight years old, you’ll be as good as done with pruning, save for the rare occasion. Your tree will be sturdy, strong, and healthy. It’s still a good idea to inspect it at least once per year and give it a good once-over after any big storms.
If you’re ready to plant a new tree, or if you need advice about pruning the trees you already have, stop by our garden center for a visit. We can help you figure out the right solution for the trees in your yard.